I've never heard of anyone having problems with their hardware not coping with the mods. Then again, your GPU is prehistoric.
You should be able to easily run this with any $50, 512MB graphics card from newegg (or your county's equivalent); I've run the game flawlessly with the graphics overhaul in a laptop using a GeForce 9600M GT. I don't see your RAM being a problem, but maybe it would be better to upgrade that a little, if for no other reason than making your whole system run better. 2GB should do the trick.
Frankly, however, if your rig is that old you'd be better off building a completely new one. You can probably cannibalise your old HDD, RAM and case, so it would take less than $500 for you to build a system that will easily cope with the game and feel far more responsive.