Mine is fan cooled as 4 of the 5 channels are class A/B and JL's are not known for their efficiency beings that they are pretty tightly regulated. That being said I disconnected my fans last fall and have been watching the heat to see how much I can throttle them back.

I hate to admit it but I may compete a couple times this year.

Keep in mind that my false floor is fractions of an inch above the amplifier, it's VERY TIGHT in there. if you are going to use the whole well, for a couple amps then I think they should do OK as long as you keep the impedances reasonable and run sensibly. You don't need a cap, save that money and buy a better AGM battery, the whole car will thank you.