I recommend a lower profile ram. I recommend the 1.25v G.Skill Sniper 2x 4gb. Speaking of ram, 16gb is too much for gaming.
I also recommend dropping the large hdd for now until the prices drop. For now, a 500gb hdd is enough. If you have a spare one you can use that too.
A good gpu is the 570 fermi.
No, I definitely need 2TB, I have two completely full 2TB external hard drives sitting on my desk right now...
As for ram, will 16gb necessarily be a bad thing, as in, will it worsen performance? I do a lot of activities that require a lot of ram, and 8gb is easily being completely used on my current rig.
If I do get a 570, do you think anything will be bottle-necking my system? If so, what?