Upgrading GFX and a few other bits. Any Advice?

[jimmyob]

Hi Guys,
I bought an HPE-063uk last year and have been wanting to upgrade the GFX card for a while now. It's currently got a Geforce 230GT 1.5G which seems to be the worst GFX card going and is therefore not on general sale.
Overall Specs are:
Intel i7 860
8GB DDR3-SDRAM
Geforce 230GT

I dont really know much about PC's anymore and was hoping someone could point me in the right direction.
It's mostly for games and would be looking to spend around 200 on the card and then 100 on any upgrades to the PSU.
Does anyone know if it would need an upgraded Mobo as well?
I can go Nvidia or ATI dont really have a preference.
Any help would be greatly appreciated thanks,
Jim

 

[jimmyob]

Shadow, current res is 1280x1024 but i do sometimes whack stuff on my 32" not sure of the res on that.
not sure of the current PSU output and havent managed to find out on net. I've heard it's around 430w.
Any more help would be great.

 

[jimmyob]

ok thanks,
I'll go have a look tomorrow.