First thing to try is the TriCool fan's setting. Is it on low? Can you tolerate the noise at medium? Etc.
Still, I'd probably take the TriCool that's in the back, put it in the front, and add an Arctic Cooling exhaust-only fan to the back with something to downvolt it. A full-blown fan controller could be used for full front & back tuning, but one or two Zalman Fanmates could work.
I suggest this because I think the AC fan gives a good flow / noise ratio (just pushing a button, don't take this literally; I agree..)
However, this goes against Galvanized's caution about ensuring airflow through the PSU, which is not really my intention. I'm simply assuming that there will be enough airflow through the PSU. If there isn't; if it starts getting hotter, then you should change things around.
The only thing that will actually cool the internals better is more airflow (whether overall or in detail), and you can judge the overall informally by sensing the exhaust fans output and more formally, via results, by measuring the internal temperatures.