Nice project GG. Good luck!
I have w2k at work in a box with similar specs, it takes about 10 mins to boot too, and to start software is also something to think about. I throw all the ram I could find in the factory on it though, and once everything is running, multitasking is ok. I have a hardware firewall. I decided to turn off antivirus, because oh my g0d, they are worst than viruses in this machine, they turn it unusable.
Do the printing through samba since you're going to get that running anyway. That way you'd have the Windows drivers and wouldn't have to worry about inadequate Linux drivers for the Lexmark.
I was reading about printing with samba the other day. I don't have the magazine with me here, and can't remember the exact procedure, but it was a matter of single line in a configuration file, and a couple of clicks in Windows.
So I'll see If I can find it.
So when you are not at your computer, you are reading about it. Ummmmm, sounds familiar...