Theoretical Linux Lab architecture.

Hi all,

I'd like to have a discussion about a theoretical lab. (For the background of why I want to have this discussion, please see my follow-up note that is posted somewhere below.) I've phrased this as a kind of case study but any type of open discussion would be ideal.

Overview of the existing environment
This lab is intended for a school environment (grades k-13) and will be used by students to teach fundamentals of computers including, but not limited to Windows basics, Word Processing/spreadsheets/presentations, Java programming (and perhaps other languages such as PASCAL). The lab currently consists of ~125 client Windows machines with no file servers. Of course there are a number of constraints that will limit possible solutions. The network internally is relatively up-to-date (Ethernet, 10mbps+) but there is only 1 DSL internet connection for the entire network.

Goals for the lab
1. Work within the constraints to optimize the best use of the given budget without reducing any current functionality and increase the options for learning.
2. Improve network control. Limit student's ability to install unauthorized software and optimize the limited bandwidth to the internet.

Goals for this discussion
1. Gather some ideas on architecture of how a theoretical lab might be designed so that I can propose a different view point to those in charge. This is not for profit, and if you read the background post below, you'll find this is to help remove the blinders from the Principal's (my mother *sigh*) eyes.
2. Gather some real-life numbers so that I can find the minimum requirements for servers and workstations.

Constraints
Monetary - Budget of ~ $24,000-$30,000cad ($18,000-22,000usd) for new hardware, hardware upgrades and software upgrades
Social concerns are in favour of using a Windows desktop because of the financer's comfort level.
Technical - The existing technologist is low-skilled so an outside resource will be required.

Options...
The options are quite varied so I'm interested in hearing all of your thoughts. I don't want to kaybash any ideas just yet but let me try to throw down some guidelines;
1. Currently, the plan is to spend ~ 50-70% of the budget on a Dell server with the remainder split between hardware upgrades and a low-cost consulting group to implement a Windows network w/file server. This is the worst case scenario...
2. A complete and/or sudden conversion to Linux/XWindows is unacceptable because of the social and technical constraints above.
3. The solution must be geared towards a risk-adverse, prudent deployment. (read:Slow and cautious)
4. The solution must include the ability to run a graphical windows manager on ALL client workstations. Software must include an office productivity suite, java compiler, web browser (further requirements still pending)
... I'll add more restrictions later, if required ...

Now... lets hear some ideas!

[edit: fixed formatting]

Background...
My mother is the Principal of an upperclass private school in the Caribbean. (I will withhold the location as I haven't received her permission to post this yet). When taking over the position a year ago, she was handed a dilapidated computing environment which she has since improved (I think doubled in size) so she now has ~125 machines. She is non-technical and her only advisor is a low-skilled technical person so by default, her awareness is association with Windows and "catch words" like file server, firewall, router. She has earned a new budget to upgrade the computer labs once again and has asked me for some advice on where to spend the money.

Why me? I'm her techie-geek son that works for an International eBusiness firm and have 'inside' connections to places like this that would otherwise be unavailable to her.

Why do I care? Hey... it would be cool to help out this school and put the "Linux can be a viable alternative" theory to work. I'd like to see a practical application of Linux integrated into a real-world Microsoft environment.

My first thoughts...

Ok, my first thoughts are this;
Although I'd like to see a complete rip&replace of Windows (My own personal bias against Mr. Gates & co.) that wouldn't be a practical/acceptable solution. Therefore, I'd like to see a phased approach for adding Linux desktops to the environment and an immediate implementation of Linux as the OS of choice on any new file servers, routers, firewalls in the environment. Perhaps you can suggest some numbers 'cause I know nothing about server sizing a linux box in an education environment.

I would propose that phase 1 of the upgrade be to a) implement a pilot linux lab of ~20-25 lower-end machines. b) upgrade lower end hardware/software as far as budget constraints allow. c) Leave higher end machines virtually untouched. I would suggest that Win2K be used on all Windows desktops, and an undetermined distro (Fedora? ) for Linux Desktops.

On the server side, I suspect the planned Dell server (~$15,000cad) is a dual processor machine with 512MB or 1GB of RAM. And can be used as the main file server for all clients (SAMBA and NFS?). I would additionally suggest that one of the older machines (assumed pentium class) could be used as a filewall/router + ftp/http server. I think that if the Dell server is overloaded, that another regular PC would suffice as the NFS server for the Pilot linux lab.

Phase 2 of the approach would be to convert all lower end machines into Linux workstations split on a 1:1 ratio with Windows desktops.

I see some big holes in my solution so perhaps you guys can help fill in the blanks... Firstly, what software is available (budget budget budget) that will help control software installation on the windows machines.
How will the file sharing work? The users should have access to their data from both Windows and Linux desktops.
How will X be configured? Does each workstation have its own X server or is there one central server where X is booted from? I'm not too familiar how X servers are architected in an environment other than my standalone systems at home.

Software isn't really a big deal, I know java is available on both OS's, as are Office suites. Can you suggest any additional software for education?

By no means is this a solution I'm married to... it is just some first thoughts. Lets hear yours!

Files server: hand build (eBay parts) dual AMD XP 3200+ 1GB DDR, 4 96GB SCSI Drives in Raid 0+1, Gig Ethernet. ($4000us-$ 6000us)

Linux to Windows: Start with of the High end boxes ~25 linux ~100 windows and slowly move all to linux

Network: upgrade to 100mbs (ebay) use SMB & NFS ~$1000us - $3000us

Linux office: OpenOffice

X: each box should have its own x server

Distro: RH9 or SUSE

Software Installation: Google but computer techies can break most of them in 10min

I think I got everything

eBay is your friend