I'd recommend a SDD, trust me they are 100% worth it. I bought a HDD the first time (1TB as well) and it was okay. But then I upgraded to a SSD, and man I can't look back it's so damn fast. Windows boots up instantly. Games that require info off my drive are near instant. It's awesome trust me.
Only downfal is that they get expensive for a lot less space.
Parts fitting, well that's a small case (it looks like) I don't know there exact dimensions but looking at the Coolermaster website and at that case specifically you can remove the HDD case for if the card doesn't fit properly.. Though if you are worried about size I would go with the HAF series.
Thank you all for the responses, I dont have to go with OCZ, i thought it was a good brand. However, after reading your replies i have no reasons not to pick up that corsair psu u suggested.