Howdy!

I've been looking around for a good Document Management system to use for my small business. Seeing as SAP or Citadon are a little above my price range, I was wondering what you guys would recommend. Let me define a little better what I'm looking for:

I have 6 "classes" of documents that I need to keep track of:
- Word Processor Documents (some in .doc, some in .sxw) that I can edit
- PDF Documents that I can send to clients and partners (for the official feel)
- Pictures from when I have to go on-site
- Technical Diagrams and Drawings
- Calculation and Experiment Documentation (from MathCAD and ANSYS, mostly)
- Templates

Here is my general process of doing a job:
I receive a project RFQ, I put together a proposal (Written in OpenOffice). This generally goes through 2-3 revisions which I don't really need to keep track of. Then, I export that document to a PDF and send it to my potential client. If all goes well, the client and I negotiate the scope of work and compensation, and I reflect the results of those negotiations in my proposal (Now in Rev. B) because it will later serve as a legal document.
If I am awarded the contract, I will run my experiments and calculations and keep all of those documents segregated from each other. Every Monday, I prepare a status report and send it to my client (In PDF form) keeping them appraised of our status. If I have to go on site, I bring my digital camera, and take proliferous amounts of pictures (I've been averaging about 200 pictures/day recently). I generally have an intern filter through the pictures and highlight the ones that will be useful and just zip the rest of them up and throw them on our storage server (where our files go to die).
At project conclusion, I send out a LOT of documentation and due diligence documentation. What I like to do then is sit down with my team and review everything that we did, what went wrong and what we can do to avoid similar problems in the future. This generally involves pouring over the documentation's old revisions to see the evolution of the project.

What has happened recently is both good and bad. We've had a surge of new business, and we've had to hire new people. Previous to now, everyone in the office had an "agreed-upon" naming convention for files, and where to put things, etc, etc. With the new guys not learning the system well coupled with the ton of work, our document organization system is in need of repair. On Wednesday, we almost lost a lot of old revisions, which could be VERY bad. Thus, why I need a document manager.

What I would like:
- Naming convention enforcing
- Revision Control
- Easy-to-Understand Heirarchial relationships (So I can group .doc and .pdf files that are the same document under the same "overclass")
- Web Access is a plus
- Needs to be able to handle large files quickly (I have some 3D models that are GB's in size, and I don't have time to wait 2 days for them to load)
- Good access control.

So, do you have any recommendations? Any success stories? Any caveats? Thanks so much in advance.

There may be something usefull at http://linas.org/linux/pm.html (cached) . Something along the lines of CVS or SVN might work, but the command line interface can be a bit of a challange. There are good front ends for these as well. As more and more desktops move to Linux and ODF, you should start seeing these develop rapidly. Necesity is the mother of innovation (unlike $$$ as some companies think).

Sorry I couldn't be more helpful.