about the triad ballasts, yes they get hot, but does that matter? I put both my ballasts inside the cabinet and put a clip on fan pointing at them. I can't even hear the fan at all because it's in a closed environment. After running the bulbs for 12 hours with the fan on, they are not even warm.
I suggest the clip on fan or ease of use and price. Like I said, I can't even tell it's running.