Up to the T7600G will work, although you won't be able to overclock unless you could force the bios to become a m1710s. Which shouldn't be an issue...really...since the boards are damned identical. Be sure you get a FCPGA and not a FCBGA though, lest you want to be soldering it permanently. :P and it being a socket M too.
For Vcards..you can put from 7800-7950 go gtx in there, quadro 1500-3500, AND a quadro fx 1600M OR 3600M (Kinda).
The bios doesn't recognize the newer cards though, I heard that the 1600M works, but there was a whole thread here about the 3600M kicking ass but lacking a lot of controls, mainly the ability to turn on the inverter (dark as shit screens).
The 1600M 'would' kick the 7950 gtx's ass if it weren't so limited by a 128 bus.
Thus the best one really is a 7950 gtx or quadro fx 3500M, whatever's cheaper.
I might try making a manual brightness control switch in a couple years and upgrade to the 3600M though for shit n giggle.