I would add two 120mm fans at the top of your case, exhausting heat outwards. Also, tweak your fan profiles on your gpu, and keep it a bit cooler.
That should help.
One 200mm fan would be more silent though...
TC you can't take an intake fan in the bottom?
Nope afraid not, the PSU has it's own fan grill down there, but no space for case fans.
Thanks for the input everyone.