I would recommend this, if you're serious about the whole editing thing:
Intel Core i7-3820 @ R3240
Intel DX79TO Thorsby @ R2629
TEAM Xtreem Vulcan DDR3-1600 16GB @ R764
KFA² GTX660 EX OC 2GB GDDR5 @ R2682
ADATA SP900 128GB @ R1334
Western Digital Caviar Red 2TB @ R1271
Antec Three Hundred Two @ R727
Antec HCG-M 520W @ R770
Total: R13,417
It is pricey, but there's a good reason for it. As time goes by, you may want to dedicate some RAM as a RAM drive to act as a cache for your Adobe software, as this has been shown to improve performance far more than any single SSD can accomplish. With the eight DIMM slots available, you can pack a crapload of RAM onto there, reserving half for your RAM cache. In addition, you'll receive platform support for at least another whole year while Ivy Bridge-E is still kicking, giving you lots of options to upgrade the CPU later on if you need more speed.
Quadro cards can be a good pick, but they're generally more expensive than the AMD FirePro models and aren't always faster. They're better suited for working with 10-bit video and a 10-bit monitor. Aside from those two things, they're nothing special. Obviously CUDA does play into things a bit, so if you're looking to use plugins with After Effects that use CUDA, Nvidia is the way to go. Even though Adobe doesn't certify the GTX660 for use in A.E. CS6, you can do a small edit to the .ini file to allow the software to use the GPU for CUDA acceleration.
Studio 1 Productions keeps a nicely updated list of Nvidia GPUs for use with A.E. and does link to the method to get CUDA to work with any supporting GPU.
If you want to save money and get something cheaper (possibly smaller, don't know if you're into that), here you go:
Intel Xeon E3-1230 V2 @ R2852
MSI H77MA-G43 @ R888
TEAM Xtreem Vulcan DDR3-1600 16GB @ R764
ASUS GTX650 Ti 1GB DDR5 @ R2063
TEAM Xtreem S3 120GB @ R1087
Western Digital Caviar Red 2TB @ R1271
Cooler Master Elite 344 @ R323
Cooler Master Silent Pro M2 420W @ R701
Total: R9949
Cheaper, smaller, more efficient. Don't think I need to go into any more detail here. Of course your chassis preference might differ, but this is what I'd go for if I was in the market right now for video editing.