What about cutting an opening in the FRONT Large enough to view the amp, but still leaving enough material for stability. Say a 1.5" to 2" edge. Then with some small trim pieces frame it out so you can add a piece of 1/2" lexan with 1/4 round on the front. Then port the front with 4-1" holes (in the wood) and screen them on the back side. Close the back up with 1/2" lexan and put a couple of 3"-4" fans pulling out. Fans up high in the back. If they fail you'll still have a convective effect.