7600GT replacement needed

[Arthalen]

Missus is having new SFF PC built based on the Antec NSK1300 case.

Originally, this was going to have her 7600GT installed. However, despite the upgrade from a X1300 Pro, lol, she still gets a bit of video lag when she's gaming on F.E.A.R.

FEAR is being played at 1440x900 on 19" WideScreen
The PSU spec for the case is 300 Watts with 18 Amps on the 12v rail.

Can I cram a better card in here, or is the PSU going to suck ?
CPU wise, I'm looking at the X2 3800 Energy Efficient model paired with 2x1GB DDR2-533.

So, any ideas ? Nvidia only please, she only plays FEAR mainly and my X1900GT seems to suck at it, but handles everything else fine.

Oh, budget: Anywhere between £100-£200.

 

[Arthalen]

I think a few people are misunderstanding me.

The new card is *not* for me rig (that is in my signature below).

Its for the Wife. She's having a new SFF PC built, that has a 300Watt PSU with 18 Amps on the 12v Rail. She was going to have a 7600GT Card put into this new machine, but seems she has occaisonal Video Lag when playing FEAR at 1440x900 on a 19" Widescreen monitor.

Question is, whats the best Nvidia card that this PSU will support ?