SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: gaming, (World of Warcraft, Stracraft 2, Dragon Age, Diablo III, Supreme Commander) surfing the internet, watching movies
PARTS NOT REQUIRED: monitor, and speakers, (Keyboard and Mouse if the MOBO has PS2 ports)
PREFERRED WEBSITE(S) FOR PARTS: http://www.overclock.co.uk/ others are fine it's just the one that came up cheapest on the few parts I ran a compare of.
COUNTRY OF ORIGIN: UK
PARTS PREFERENCES: Some preference towards Intel, though I could be convinced.
OVERCLOCKING: Maybe, while I've built PC's before I've never OCd them, though I am interested in doing so. As I'm upgrading from a really old machine I probably will run it at stock speeds for a while first.
SLI OR CROSSFIRE: Maybe, probably not to begin with but I wouldn't mind it as an option for an upgrade unless it adds alot to the price and I would be better off just upgrading via a new GC. - Thinking this would be in a year or so.
MONITOR RESOLUTION: 1680x1050, for now I'm hoping to get a slightly larger monitor as my Next main PC related purchase so then going to 1920x1200 with the current screen as a second monitor.
ADDITIONAL COMMENTS: (I would like a quiet PC), Given how long my current PC has lasted, about 6 years, all be it with a few replacements and minor upgrades here and there I'd like a build that can with maybe a new GC last a good few years.
There's no point cross firing a 5870 with a 5770 as the 5870 will down clock to 5770 speeds. You're better off spending a bit of extra money to get a 5850 now and dropping another in at a later date.
I'm actually looking for a system similar to yours, though mine's coming closer to £900 with the OS, though I've not seen the website you're using before, so i'll be checking my prices against that to see if I can reduce my cost at all.
Also, as you're into gaming I'd suggest a gaming mouse as they make a big difference, I actually used to have the Logitech MX518 Optical Gaming Mouse a few years ago, but have been using a G5 for a few years, but my next mouse is going to be a Logitech MX518 Optical Gaming Mouse as it has an extra button which comes in handy, especially in WoW and other games that require buttons. I've seen them for £20 or so.
No it only has one PCI-E slot. It looks to me like this is the cheapest available mobo on that site that can crossfire: Asus P7P55D EVO £127, So you will either have to go over budget more, or cut back somewhere.
The stock cooler will come with some thermal paste preapplied, so there's only really any benefit to this if you are going to get a CPU cooler, which probably would be a good idea to get one if you're going to overclock. You could of course wait until you do want to start overclocking, might be a good idea when you are replacing graphics card to take it all out, have a good clean and that would be a good opportunity to shove a heatsink in there.
"As you can see I'm somewhat pushing my budget especially as I was originally hoping for £700 before the OS."
Changing to a Phenom II X4 955 based rig would save you money on the processor and probably the motherboard (or get a better one for the price), and in gaming the CPU is not nearly as important as the GPU and when it comes to gaming a Phenom II X4 955 and Intel i5-750 are on a pretty even playing field, the Intel would be better in things outside gaming in CPU intensive stuff such as video editing. Altho I think that the Intel would have a bit more longevity, however there are already 6cores out on AM3, so maybe it would easier to replace it if it became inadequate.