Any wireless router should suffice... most popular brands would be Linksys, D-Link, and NetGear.
From my own personal experience, the Linksys WRT54G is a good one... various NetGear wireless routers are also great.
What screen issues are you referring to?
As far as I know, the W3V was a great machine... and all computers have a chance of overheating. I'm sure the W3J produces just as much heat, if not more heat than the W3V.