I have two blackjackets, one for 4x5 and the other for 8x10. For 4x5, I found the 40 inch very gave me alot of extra room that I needed. I suspect the 32 inch will be a very tight fit. Email Keith, he is a super nice person to deal with!
The hybrid is quite a bit cooler, but not quite as dark inside. I personally find th weight difference to be minimal. When I am already carrying 10+kgs of gear a few extra ounces are nothing.
Personally I want a dark cloth with a real built in A/C unit, in summer I sweat like crazy when I am under the cloth.
Hope it helps.
Gary