I'm' a big guy for biking at 220 and I've been as high as 250
my first ride had double walled rims but nothing form a haro excape 8.2 and my new rig which I bought at 235 uses bontrager race lite wheels
unless your doing drops larger than a few feet I don;t think you'll need to worry much about wheels I've personally not had any issues with either of my sets
I ride with a few bigger dudes too and no one riding rocky XC here is destrying their wheelserts but we generally do ont do any drops and jsut roll off the 2-3 foot stuff