Ubuntu Servers :: Setting Up Home Server With Backup Imaging For Clients?

I'm trying to setup a server at home, it has some practical implications, but largely it is just to take a stab at it. But I need the help of someone with more experience than I in defining exactly what I'm looking to do.

Here's what I have: old PC running Gutsy server connected to router. Several laptops at home connected via wifi to router. All laptops running either Windows or Ubuntu. Here's what I'm looking for: The server centralizes file storage for all clients. I would likely incorporate a RAID and some synchronised imaging of the files. I also want the server to create disk images of the clients hdd, regardless of client OS.There would also be some shares that would be publicly accessible (myself and friends accross the country would be able to access the same drive).

So I was thinking something like what corporate environment would be nice, you log into a profile that exists on the server. Like a dumb client...all data would be stored on the server. But I'm thinking that's more like a network boot and wouldn't work via wifi (or would it?). Also that wouldn't lend itself well to laptops used on the road in areas without net access. now I'm thinking each client would have its own locally installed OS, and they would just access networked shares. I could store sensitive files on the shares, but that wouldn't provide complete backup solution for each client.

Without rambling on anymore, anyone care to throw out some ideas? I'm really just looking to see if I can do what I want. The focus is on centrallizing files, securley backing up data and client OS's and ability to restore said images quickly.