alright so my school is trying to get macs and pc's running side by side, and they are about to spend 3500 on an extra server unless i can convince them that linux can handle both from 1 server. so i am wondering if it is possible to have roaming profiles for windows and mac, i have looked into samba a little bit, but i only need that 1 answer. will a linux server give roaming profiles to mac and pc, and interchangably so people here can access their personal folders from either?
also what would be better with linux, a 3500 mac server or a 3500 pc server - windows?

any other suggestions or anything would be greatly appriciated.

Samba can certainly do roaming profiles for Windows machines, and assuming Mac OS supports them, it should work as well. Samba can easily replace a Windows NT4 style domain controller, though the last time I worked with it, Active Directory support was not quite there yet. You didn't specify anything about the current network setup, so I don't know if that is going to be a problem for you.

I am not 100% clear on what you mean in that last bit, I guess you are trying to ask what the better hardware would be for $3500. Without a lot more information on your needs and the topography of your network (how many users are we talking about, how much space is each one allocated, etc, etc), it is pretty much impossible to make any sort of hardware recommendations.