Most of the PC's are listed in dollars and use american sites, I have a budget of around £600 to build a new PC

My current setup is:

Intel Dual Core e2140 @ 1.6Ghz
2GB DDR2 Memory
320Gb Samsung Sata HDD
Gigabyte 9800 GTX 1GB Gfx Card
500W Power Supply
HP 2009v 20inch Monitor
Sata DVDRW
Im looking to upgrade, and was wondering if anyone knows of any sites that sell good spec second user PCs (and/or Parts), something in the i3/i5 range I think is probably the max of my budget even with second user parts.
I would like a SSD and Razer naga but I doubt I am going to get those in the budget from day 1. Are there any parts I should reuse, maybe the GFX Card or should I just start from scratch :P

---------- Post added 2011-07-30 at 09:12 PM ----------

Bump, any advice would be appreciated, or if anyone knows of any sites other than ebay, scan and overclockers