I agree with the suggestion to use Rena air pumps. I use nothing but them (one 300 and four 200 models) on my tanks and they are quiet and powerful. They are also easy to maintain (I get the parts from www.thatpetplace.com
). I would recommend the Rena Air 300 at a minimum for a 75 gallon tank although it depends on how many devices are going to be attached to it. I suggest using the Micro-Bubbler as your air stone.
Gene Heitman - 12 tanks (11 freshwater and 1 saltwater), 206 gallons, 20+ species of fish/shrimp/snails, 52+ species of plants ... 10 years ago I just wanted 1 tank with some fish