SSD: Be warned that these things are constantly changing and are often problem-ridden. In coming years this technology will either become obsolete or much lower price per GB. this one looks great for a smaller OS drive if you are willing to add it later or increase your budget http://www.newegg.com/Product/Product.aspx?Item=N82E168...
the install space requied is 16gb but you will need more than that if you want to install anything. 64 is a good size because it gives you room to install some programs and an OS without totally filling the drive.
Total: $1478.22 shipped before promo code and rebates
If you don't need the OS, upgrade to an i7-2600k. It will help with the multitasking. I would go with that over 16GB of RAM right now for the simple fact that RAM can be doubled later if needed. An SSD can also be added later, and will only decrease your boot time into Windows and the time it takes for programs to load.
The R3 fits GPUs up to 290mm and that 6950 is 275mm.
the fractal design XL will have even more space, and it is priced around the same as the HAF. The HAF is pretty quiet, but it wont as quiet as those other cases that have foam and fan controllers built in. The HAF will give you better temps but be a bit louder
You truly do not need a 2600k unless you need hyper threading, which does nearly nothing for video and gaming. Look at these benchmarks. http://www.anandtech.com/bench/Product/287?vs=288
the 2600k is not worth the 100$ over a 2500k
The twin frozor 6950s will already be quieter and cooler than the reference design models and wont need additional case fans