It is important to know what exact main edit suites you intend to work with.
Most important ... Do you fully intend to use Avid or Premier (any flavors) as your toolset.
This matters ... and, if it is just home video and "art project studio" and consumer/prosumer bit-rates at or below 27Mbits/sec., then you may not need that workstation card (or even an expensive gamers card) because, you will be working in Vegas-Pro or Liquid-Edition and CueBase, etc., which do not care much, if anything, about graphics, except for memory and a modicum of speed.
Hard Drives - Check out the performance charts and pick whatever 500 GB per platter drive performs best under your usage patterns. The 2 TB WD Black and LX from Seagate are good choice but at smaller capacities, you are limited to the Seagate 7200.12 or the Spinpoint F3. The 7200.12 excels in gaming, multimedia and pictures whereas the F3 wins at music and movie maker. See the comparisons here (copy past link in manually, link won't work in forum):
Look at the tests that reflect your usage and choose accordingly.