Hooy

250gb is the sweet spot in terms of space and price. I wouldn't get anything lower than that at this point, especially since it's only an extra $70 additional investment these days.

If you can find another used 670 for under $200, just SLI. I got 2 Power Editions used for $420 before the 700 series was even out, so it shouldn't be too hard. If not, wait for the 780 price drops coming since the 290X is out.

personally i would save some money and get a 1600 mhz ram kit. the real world performance isnt there for anything faster.

everything else looks good

i got my rive off ebay for $220 a while ago a 690 off craigslist for 600. look around, new egg isnt always the best

1600mhz is a standard now, so I wouldn't go below it. The cost is so insubstantial