I dont think a little warm is going to be a problem.
I have very little breathing space around mine and have had no problems with shut-down.
I had a small fan hooked up to the back of my cabinet and it really worked well, but it was VERY loud, so I took it off. I did see some on e-bay that were built for this purpose that were supposed to be silent. I'll post a link later when I get home.

LIFE IS SHORT.
DON'T BE A DICK.