Want an upgrade on an old system - which gfx card?

O.K... So I have a six year old P4 1.5 Ghz / 384 - 32 (Onboard Video card) = 352 MB SD RAM / S3 Graphics Pro Savage DDR   on Ubuntu 8.04...

Well, I'm having lot's of problems especially on Blender and games... The gfx card can't even run Blender and Google Earth. So I think I will upgrade my graphics card and buy about 512 MB of Memory(I would have to remove a 128MB memory stick)... The Memory would cost Rs 1000 (20$) But I can't decide on the Gfx card to buy. I would like to work in Blender, play a few FOSS games and work with OGRE. I would like to buy a cheap GFX card that goes well with my processor. I CAN'T buy a new system now. I would like to keep this system for one year more before I buy a new one. So here are the choices for the AGP cards :-

1)Palit FX 5500 :- Rs 1800 (About 40$)
2)GeCube R9250 :- Rs 1900 (Also About 40$)
3)GeCube R9600Pro :- Rs 3100 (About 60$)
4)GeCube Rx1600Pro :- Rs 3900 (About 80$)
5) POV 7300GT :- Rs 3800 (About 80$)

I think an FX 5500 or a Radeon 9250 should do. That is what I actually plan to buy. But if that is completely bad, I might settle for a Radeon 9600 Pro. I don't think my processor is that good for a 7300GT. Also I have an AGP 4x Slot.

Another noob question :- Will these cards take memory from my system RAM like an onboard solution does? I don't think so...

Please help.