I personally doubt the problem is with the caps... they seem to withstand heat pretty well (most standard caps are rated to 105 degrees C, which is over the boiling point of water). I'd definately get a can of freeze spray and try cooling components (chips and transistors are usually most affected by the heat, which is why those components usually get heat sinks). It's possible that moving the caps would allow better airflow and allow it to cool better, but you have to be careful when moving caps because if you put too long of a wire, you lose some of the effectiveness of the cap.

IMO, I'd try cooling the amp, as these are usually what gets really hot and fails. Also, is there a volume control on the system itself? If there is, you should turn that down and use more volume on your TV (or maybe the modification should be to decrease the amplification). Maybe check the voltage to the amp too.

DogP