I would be paying around £300, and using it for normal things internet/typing as well as design programs which are fairly heavy. I'm particularly interested in the graphics cards as I have little understanding of the numbers. I'm currently using a macbook.

Packard-Bell iPOWER X 2.0 PC
Quad Core Intel Core 2 Quad Processor @ 4×2.34Gzh
Supporting the CPU are 4GB of RAM and a Fast 600GB Hard Drive

The system sports not one, but TWO NVIDIA GRAPHIC CARDS
Powerful NVIDIA GTS 250 (9800GTX+) Graphics and one additional GEFORCE 130GT card for NVIDIA PhysX

All these components are housed in one of the best computer cases available, the iPower X2.0

POWERING THE WHOLE SYSTEM is a TOP-OF-THE-LINE ModXStream-PRO 700W MODULAR power supply.
It ensures that all components receive sufficient power constantly and eliminates any risk of damage due to shorts etc.

thanks for any advice

For 300 quid, it looks like a bargain. As for suitability, that'd depend entirely on what these "design programs" are?

Didn't know Packard Bell were still going, I thought they went under years ago. Could be wrong, but I wonder if someone's bought the name; in which case, I'd check that you can get decent support on it if you've got issues with it.

The system sports not one, but TWO NVIDIA GRAPHIC CARDS
Powerful NVIDIA GTS 250 (9800GTX+) Graphics and one additional GEFORCE 130GT card for NVIDIA PhysX

This confuses me. I'm a little out of touch these days, but I'm not sure what the point is of this. As far as I was aware, the 130 series cards don't support PhysX. Quite what the point of that second card is, I've no idea.

I think I'd get no support as private seller.

Perhaps I'll steer clear

sli?

700W power supply? Blimey, you won't need a heater in the room…