GPU for a P4 CPU Comp

Well my brother's gpu finally kicked the bucket and died out,
He had a 2600 pro 512mb pci-e card which was fairly good for the age of the system.
The computer he has is actually my old computer which i had custom built for me YEARS ago
the sepcs are:

Pentium 4 HT 517 2.93ghz
Foxcoon mobo (can't remember the chipset of it atm but it was defo before pci-e 2.0)
1gb 4200U DDR2
350 watt psu (the original was a 550 watt but that died out too)
80gb ide hdd

So what would be the best GPU I could get for this system without bottle necking or down grading from the old card?
(BTW the card needs a hdmi port with it's own audio as the mobos onboard audio is fucked aswell)

I'd get a NVIDIA 7800GT or a ATI 2900GT

Go for a 9400 GT, I bet that would work great.

8400GT should work just fine, and they've gotten very inexpensive

9400gt

wouldn't the 9400 gt be a downgrade tho beings that it's gddr2 rather then gddr3 like the 2600pro?
btw he does play a few basic games but nothing to demanding.

ok i just decided i'm going to upgrade the whole thing to make it into the best possible p4 gaming rig by changing out the psu, memmory and the gpu.
going to upgrade the memmory to 2gb since that's all what the mobo can support and maybe a 500 watt psu but i'm still looking for suggestions on what gpu to make it the best it can be without bottlenecking.
(the computer is still technically min e he just has it in his room and uses it)

If a 9400 GT is too little, then maybe a 9600? I'm thinking that might bottleneck.

well the 2600pro didn't bottle neck even tho i was highly expecting it would so i think a 9600gt would just pass but by the smallest margin bottle necked, i'll get alend of my gf's 9600 and use that to this test this

how much money are you willing to spend.. BTW there is no need for that large of a psu. 400watt is perfectly fine.

I was running an xfx 8600gts xxx for a good year with a Pentium 4 [albiet 3.2GHz, but still] on a 420W PSU. So a 9600gt would be fine, or a 9500gt.

On the nVidia side of things, anything up to a 9600 GT would work fine, and not require much power either. At the price of the 9600 GT's new these days, I would go for a used 8800 GT on eBay if I were you. (would bottle neck, but for the same price, why not get more for less eh?)

On ATi's side, I would say anything that is X670 or below (Ex, 3650, 4670, 5670). If getting an ATi card, I would get one of the newer 5XXX series as they are VERY power efficient, and the lower ones are also now really cheap.

if i get a new psu for his comp i'll get a 8800gt if i don't i'll got with anothewr 2600 pro or maybe a 5670 since it's massivly power efficient, thanks guys for your help