May be getting way off topic now but if you like your mobo and cpu, and are planning to keep them around a while, maybe a case swap and powersupply upgrade first? then you can get any gpu your heart desires.
Just an idea for an all in one solutionhttp://www.newegg.com/Product/Product.aspx?Item=N82E16811129024
otherwise i've heard great things about the 4670, small, low power draw, decent performance. Never used one though, switched to team green when i took up linux.
So from there there are 9600gt's in single slot designs now.
Just to get way way off topic what ever happened to the 4770? I know the when the price dropped on the 4850 it all but fell off the map, but do you think that the lower power requirements of the 4770 might work in his case with the 350 watt oem'er he has? Or is he gonna be solely limited to cards powered off the port with that?