AMD is better in this case. If you had unlimited money and stuff, then intel i7 because it is the best CPU out at the moment, but clearly, this isn't a best of the best system.
I would go AMD then because it will perform perfectly fine with any game at all and also because of compatibility. Intel have decided to use a million and one bloody chipsets, so you have 0 upgradibility on your system without going out and buying a new motherboard if you plan to upgrade in the future. However, if you go AMd, they have 1 chipset fits all, their phenom 2 processors, regardless of the number of cores and the speed, they all sit on the AM3, and because AM3 is also a new chipset (fairly) then it will be around for quite a while still yet, so lots of new chips on it aswell for when that chip you get now is outdated.
I know you said ebuyer asewll, but just a word of advice: There are lots of better shops in the UK. By better i mean cheaper item and shipping prices aswell as better selection.
For example, the PSU you chose, it will power the system easily, but you can get the VX550 (Still Corsair, but extra 30W
http://www.scan.co.uk/Products/550w-Corsair-VX-Series-PSU-ATX-PS-2-5-year-Warranty-see-specs
for £9 less, and Scan are very very good, in so much as huge selection, fast and cheap delivery and great customer service, i know that from shopping over the internet and going to the shop itself (Bolton isn't far from me).
Overclockers is also a very good stie
www.overclockers.co.uk
It is aimed more towards enthusiasts, but they still have a wide selection of mid end system stuff and have quick delivery, wide range, cheap items and good support.
If you want to use ebuyer that is cool, but there are other, better options out there
