Are you really 6'9"? If so I can certainly see why you would want to have a riser on your air inlets. I can get away with just using magnets on the holes as I am about 12" closer to them than you will be! Remember as you build, pics are mandatory on this site... No pics, it didn't happen
Just another suggestion, notice on the pic of Norco's charcoal basket that the orientation of his expanded metal has it running the "long" way for the bend. Try doing it the other way, it will bend much easier and for my baskets I use 1/2 vs. 3/4 and they were real easy to bend and bolt to a bottom made of 3/4 for strength... His will probably last longer but I'm pretty lazy
