The mesh harness is the one I use for Raph too(though I ditched the leash that came with it...the snap seemed tooflimsy for my liking, so I bought a separate, better-quality leash). Ilove the harness though; it seems light and airy on him, and once Ihave it done up he doesn't seem to mind it at all.
As far as weather goes, Mika, I live in Ottawa, which can get a fewdegrees colder than Toronto. I keep Raph indoors for the winter, but onthe balmier days -- like this past weekend, when it was around -4 C --I will take him out for half an hour or so. He lovesthesnow...loves to play in it and follow my dog around. I think your bunnywill be okay to take outside as long as it's not frigid outside or toodamp.