Based on all the advice in this thread, moving the components is probably what I'd do. Alternatively if you're able to hack a smaller PSU into that same space I'm sure the case would appreciate the additional airflow around it. 
Good point, I think I will give that a try. I had been thinking of buying a modular psu to remove uneeded cables for better air flow. However if I move it to the Amiga psu shell maybe that isn't an issue. Or it could still be helpful. I might try your idea of a micro ATX PSU. Oh so many choices!
