Audiophiliac is on the right track. See if it works. That trumps all the calculations in the world, since this is neither actual rocket science, nor influences whether someone lives or dies.

Let's say you get all that information -- will that include the amount of spacing needed between components? Or whether air should also be blown front to back or back to front between each pair of components?

BTU outputs are not as important as whether that heat energy gets moved away from the items putting out the BTUs! Prove this by going into an 80 degree attic -- not thought of as a normally HOT temperature -- with zero air flow... see how long it takes, just sitting there, before you start to sweat.

Stick a fan in there and see what happens. Then, as a radio amateur friend of mine used to say, tune for minimum smoke.