Doing some pricing scouting, you're not getting a 680 and an i7 for £1000.
Realistically, both are in the excessive power bracket.
a 580 and an i5 are more doable and still more than enough power to last you years. In fact tomshardware are not recommending anything over an i5 for gaming right now unless you really feel like spending money you don't have to.
You could probably manage i5 + 680, but you'd be compromising on other arguably more important parts of the rig, and would probably make the SSD infeasible.
The i5+580 combo should allow you enough room in your budget to maintain all round quality in your rig rather than having 1 or 2 high end pieces and bottlenecking them or compromising them with lesser components. The LGA1155 socket allows the potential for a future i7 upgrade should it become necessary - but I don't think it will.
If you're going to insist on i7 + 680 I think you're going to have to stretch another £500 (possibly more) into your budget.
mobo ~£150 (give or take, there's wiggle room there)
580 ~£300 (depends on the model, range 230-350)
PSU £60-£100 (this depends on how much raw power you need, 600W is enough for this rig as it stands even if you add another HD at a later date)
SSD ~£70 (60GB)
HDD ~£80 (1TB)
RAM £40-£110 depending on type and amount, (8 or 16GB, lower quality or superior imo 8GB is really more than enough for gaming atm, I'd shoot for better quality 8GB safe in the knowledge that you can always add more cheaper later - so roughly £60 or £70)
Depending on what you spend on the variable price ranges that would leave you about £100-200 for an optical drive, a case and any other extras you may need (you don't strictly need a discrete sound card as most motherboards have on-board, and good motherboards in the range you should be looking at should have good enough sound).]
edit: if you can fit it in consider an after-market cpu heatsink/fan, you can get one much quieter and more efficient (giving you overclock possibilities on K series i5 cpu's) for less than £20.