Thanks all
Interesting reading.
I've decided to stick with my old systm for now, this morning I ordered GeIL 2GB (2x1GB) PC3200 Value Dual Channel Kit CAS3, bringing my RAM to 3Gb. I was limited to chioce as I presume they don't make DDR400 anymore but it seemed the best value at £105

I'm currently downloading 3DMark bench testing software,apparently it's the worldwide standard testing tool. So I'll do some before and after tests.
http://www.futuremark.com/download/3dmark05/**
**I looked at the GTS 8800 range and the card itself looked MASSIVE, not sure if they'll be enough in my PSU to power it :-( So it think I'll have a look at the 7000 series.
When I eventually get the GPU I'll look into overclocking.

Nice one for all the advice
;-) **
**