I’ve started using Foxconn’s Nettop PC’s:
http://www.newegg.com/Product/Product.aspx?Item=N82E16856119034
With 2GB Ram and 32GB SSD, that puts me at about 280 dollars. Add about 140 dollars if you stick Win7 Pro on it, although you can still get XP OEM versions for about 80.
I also have a few boxes with Ubuntu on it. They run dipslay boards that have no ActiveX requirements. If it wasn’t for the ActiveX thing, they’d all be on Ubuntu!
The XP machines are running Panel Edition with no issues as of this writing, but I’ll be sure to tell you if there is.