I've got a petzl one, I think from memory it's navaho boss (or similar). It fits my skinny body nicely and because it's designed as an abseil harness I can sit in it for hours at a time.
I wasn't cheap though but I guess you get what you pay for. It's got two front attachment points (one chest,one waist) , one rear, and D rings on the sides for pole belts. It's also got a couple of nice loops for hanging stuff from.
I find if I put a rope around a structure and then hook it to the front waist one I can sit without the belt taking the weight on my back, as a lot of the weight is transferred into my thighs.
Stu