How about spanning the 32' with steel trusses. You could face them with wood if that's the look you're going for. The K-buildings I used to build
http://www.kbuildings.com/commercial.php use some very strong, lightweight trusses and the trusses have pockets for attaching roof joists. They're fairly low profile too. I would lean toward using 3 as opposed to 2 for redundancy and lower profile.
