The big difference in sizing a server for this is that what you've described can't be tuned for any of the major server roles - file services, application services, print or comms or web services - without degrading the other roles. And tune it you'll have to if you expect to wring performance out of that platform.
Were I doing it I'd (1) purchase another hard drive and use hardware mirroring for redundancy, pack as much RAM as you can in the box, and purchase relatively beefy workstations. Workstations have gotten cheaper much faster than laptops and you could get two pretty good units for the price of a single laptop. Each kid with his own machine is a much happier scenario IMHO.
This isn't really thin-client at all but I think it might be the best cost/performance mix right now. Your mileage may vary.
(Oh, and you've probably done it by now but if you haven't, for pity's sake secure your router or you'll be sharing your broadband with the world. ;-) )
Thank you. That's exactly the kind of criticism I'm looking for. Bottom line is bang-for-the-buck. If a couple of beefy individual systems will get us what we need for LESS than the other setup would require, then I'm all for that.
(Oh, and you've probably done it by now but if you haven't, for pity's sake secure your router or you'll be sharing your broadband with the world. ;-) )
Found that advice on FR a couple of years ago. Made all the suggested changes and then some to secure the router, so I reckon we're safe enough from amateurs.