Right first off all like said, just because you have the money for it, don't mean you can spend all of it on just the base unit, just think of how many beers you can buy
get rid of the 975, and get the 920 it will not overclock no higher than you are able to do it, both will get 4.0Ghz very easy even on air, the difference between them is only the unlocked multiplier.
secondly, get only one HD5970, one is enough, unless you plan on sorting your screens out.
do you really need over 4tb of space? I would get only one WD 2TB for the moment or two 1tb and stick them in raid. the SSD is fine
you need a powersupply,
http://www.overclockers.co.uk/showproduct.php?prodid=CA-013-CS&groupid=701&catid=123&subcat=1084 don't know what else you plan to run in it so on the safe side, also you didn't state if you got one or not.
so what case you going to use for it?
RAM your best off with only 6Gb easy to overclock see, always add more, also I7 don't really seem to gain much out of faster RAM.
see now you probably saved getting on for 1k, which you can use to justify your HD5970, in other words put it in for screens instead.
also why 2 blu ray RW? why not one Blu ray RW and one DVD RW? again quite a big saving there