I would pick the GT220 from a power consumption/driver (x1900 is going to need to use the "legacy" drivers) standpoint. I would be prepared for some pretty low quality settings, but things should be playable given you have plenty of CPU. Starcraft 2, for example, is playable on a 4550 DDR3 @ 1280*1024 low/medium settings and the GT220 is much faster than that.
Seriously, I would hop on the FS/FT forums and get a GTX 260 for ~$50 and call it a day. It may not have all the features/dx levels but it has a ton of performance. It doesn't sound like an up to date feature set is high on your needs list.
Stumpy, you need to keep folding! No distractions!

Speaking of which, why aren't you getting the 2k ppd out of that 220???
