Thanks for your suggestions everyone! I'm going to look into those options.
My HAWK is like, 950Mhz and needs cooling a fair deal, think I'll put that one at the bottom and then either a TF II or some other brand at the top. I'm not sure how to put another fan inside the case - I have one on the side-panel of my Storm Scout, there's space for another but the tubes from my CPU water cooling hit the side panel so I don't think I can (I'm not sure, maybe I could move them a bit/). I have a fan at the top of the case and one big one at the front of the case. I suppose I could somehow mount a fan to go in-between the gap of the graphics card and HDD bay.
Other than that, the option to get a better single card GPU is.. sort of there.
Thanks for your help so far everyone!
If you want to lower the temps a little bit you can try rigging up a fan nearby like others have suggested, but I don't think that would be necessary.