I'd still suggest a good local PC store if your're confident they know how to build a good rig. I'm fortunate it that there is a bloody good PC store with guys who know what they're doing just a couple of miles away, wouldn't have a PC any other way now!

As for Dell, wouldn't touch them, over priced, they wanted another £1000 for the rig my local guys built for me and from what I've been told poor customer service although that is just what I've heard plus all the hassle of RTB warranties that could cost an arm and a leg because you have to insure it while it's being sent back [£60+ each time].
You need to factor all this in to any decision!

Injustice will be avenged.
Cofiwch Dryweryn.