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.
I will think about an ssd. Most importantly, will the parts fit in the case? Is the hitachi HDD reliable? And why is ocz bad?
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.