Actually i would because I'm going it myself. The system is a Dell GX280 (aka Drone) with a single x16 PCI Express 1.0a slot that currently has a Nvidia 8800GT installed. I've also had 2 different ATI Radeon 4850s and a 4870. I've not had any problems with any of those cards.
Drone --->
http://valid.canardpc.com/show_oc.php?id=2400421
GX280 specs (
Here) Seventh table down titled Expansion Bus