Thanks for the hat tip
I was a bit concerned about the foil thing too, but it's more like the dull side of foil - reflects and diffuses the light - I haven't seen any evidence of hot spots.
Heat hasn't been too much of an issue - about 12 F above ambient. The shelves that my cab is made from are totally ventilated, so the bottom is pretty much open to the concrete floor below. It seems to be pretty effective as a heat sink.
Good luck with everything!