Upgrading my old mac for cheap

Why bother?
Those are really low end cards. If they cost any more than free I would not waste my time.
Also, we need more information on your current setup.
 
No I don't game. I'm just tossing the idea around of slightly upgrading this current mac.

The specs are pathetic. 733 mhz cpu, 1 gig ram, geforce2 mx 32mb. 40 gb 5400 HD.

I want a new(er) machine. I'm torn between going back to windows, or just buying a newer g5 mac.

I primarily photo edit. I have PS CS2 for mac, so it would be nice to just install to a new mac. Web surf. Watching video on this current machine is painful. Nothing is smooth. I'd also like a lot more HD space for all my music and videos.