ive been building my own gaming rigs for around 10 years now and its much better to build your own than to pay somewhere to either build to your spec or supply a pre built tower as generally the later will have some budget - mid spec parts in there.

Do you need everything inc monitor, keyboard, mouse and speakers etc in your budget or do you only require the tower ????.

At the moment i5 is ample for gaming as you dont need a hyper threading cpu like the i7 as no games that im aware of utilise it, but having a i7 cpu means you can use tri channel memory. Sandybridge motherboards have had teething problems i think so im not sure if its best to go down that route currently, someone who has recently gone down that route may be able to confirm if theyve been sorted out. I myself have i7 socket 1366 and its a beast of a system, if you can afford £1500 then get the best components you can mate.........but some parts you can easily buy 2nd hand to cut a few quid off namely the cpu cooler and some other bits.

Actually ive got 2 x 150gb velociraptor hdd`s in the for sale section that im selling which still have just under 3 yrs left of warranty, these two drives installed in raid-0 ( show as one drive ) is probably the fastest you can get without going with an ssd which as a beginner may not be ideal but its entirely up to you mate.

Dave.