Considering the schedule, you should keep an eye out of Nvidia offering as well as the GTX6xx series should be coming out before that timeframe. And most likely you would do better with a Z77 based motherboard, which I assume will be released close to the same time as the Ivy bridge chips.
You'll should be getting a quality PSU in the 1000W range for the SLI/Crossfire and OC's.
For the best choices:
- Corsair AX1200 ~£240 Fully modular expensive but really good 80+Gold
- Corsair HX850 ~£140 Semi modular - a really solid choice 80+Silver(almost Gold)
- Corsair AX850 ~£170 Fully modular 80+Gold
- Cooler Master Silent Pro 1200 £170 Modular 80+Gold
- XFX 1050 Black Edition Pro £200
The Raven and HAF932 are both good cases with plenty of space and airflow, so they should house such a system well.
As for cooling probably at this budget some solid air cooling or possibly even a closed loop water system like Corsair H60/80/100 or then
high end air cooling like Noctua NH-D14.
Optical is pretty your pick if you want bluray or not, in any case DVD burners are cheap, Blurays a bit more.
As it stands, I would preferably stick with AMD for GPU, hopefully prices will be much lower by April at GTX release. Will keep an eye out on newer motherboards as the time comes. Will invest in better cooling if I decide to purchase a second GPU.