My setup is a single can. It's actually hidden for the most part, I tucked it back underneath the seat as much as possible, and aside from the problems I've had melting electronics around my turn signals and license plate, it's been fine.
I agree that seeing one can instead of two would look weird, and I wanted to fab it first before I shelled out money on a good one. If you can hide a can, do it, if you can't, be creative.