Re: WiFi question?
Sounds like you need to pick up a parallel port to USB convertor, then you should be able to plug in your 2100 to any laptop...your going to find most of the current print servers work only with USB, you would have to find an old one that has a parallel port on it, then it may not have the right software to run it.
You cheapest solution with the least headaches is probably going to be pick up an inexpensive wireless printer, which should work with any of your computers that has a wireless card, you can get printers with wireless b/g/n now a days, so as long as you have one of those cards in your laptops and the drivers are available, which if it is a new computer and printer, they should be no problem, you should be good to go..
Peer to peer is really nothing to worry about, most if not all wireless printers now a days, will automatically configure to work properly without the need to worry about it.
One thing to add, windows 7 has a compatibility mode that allows you to specify how a program runs, if you have a virtual capable processor, it will also allow you to actually run XP in virtual mode. I have tried the XP virtual mode and it was slow, but if you have the right processor, you can do it, albeit not the best solution.
But again, as long as the new printer has the wireless card, it should only be a very quick set up to get it going.