If you want real terminal on a network, the network is the computer kind of networking, you need to live on a client server model.
That being said, your server doesn't necessarily need to be of a Mac OS X Server variety. However, synching multiple machines without have a single authoritative source, which probably won't act like a client, is not what modern networking is about. Maybe in a decade. You get the kind of experience you are talking about if you have the user directory centrally shared, and mounted over NFS to all of the client machines. You need the machines to agree on what UID's everyone has. This is not something that's going to be easy without a server. And the only really completed solution for you at this time is Mac OS X server for mac OS X clients.
I've been living with a college sun network where your desktop follows you from workstation to workstation, and it's been great for like 6 years now. Sun: the network is the computer. But the users folder reside on a network appliance, not on any individual client machine. Our network also has a full time admin, and a couple of part time admins to deal with the complexity of this setup. It's great for users, it offers power that isn't available any other way. But you are talking about a fairly involved and tweaked experience. Not at all an out of the box experience.
You may not need Mac OS X server, but I think you need a server in your scenario. At the very least you're going to waste a lot of time getting NFS shares to happen on the command line, and you'll need to make sure you manually create users on one machine to match the other machine, and manually map the user's folder to the NFS drive instead of the normal location. That's the key, right there. I think you're going to run into permissions hell if you try to share a folder that used natively on one of the machines. ... have fun mucking about in netinfo trying to tweak all of the stuff.
Sorry I'm not helpful, I just wouldn't recommend doing what you're asking. The server product is only $500, $250 if you're in education. How much do you get paid? How many hours would it take for you to tweak this system into existence without Server? Learning is one thing. Frustration is a slightly different thing.