Personally that's what i'd do. Add W7 for £30 and a case for £50 and it comes to £1,040.

Although I see why you would want to go for the i7 instead of the i5, so you could spend some more on that instead. The graphics card is more than enough to run any modern game, I don't know what you play but a GTX380 will be more powerful than anybody needs (unless you have a 30" display). SSDs are still expensive and it would only shave a few seconds off your boot time compared to 2x1GB drives in RAID 0.

Unless you're wanting to overclock, i'd just leave the stock coolers and fans on everything. Replacing your headset is completely up to you.