Re: Advice on upgrading
The maximum wattage I've seen in that formfactor is 350 watts, so that limits you pretty bad. Granted, the GeForce 9200 is already a pretty slow beast these days, not to mention, is usually an integrated GPU.
Since you can't really upgrade to the latest gen on the video card, and the highest I could recommend on the power supply you could get is pretty tiny, a few things need to be considered.
What's your overall budget?
What's your primary goal by the upgrade?