I have CRG mirrors fit on the stock bar ends by having them turned down on a lathe. It's incredibly easy and looks good.
The CRG mirrors aren't cheap, but they are incredibly well made. I've never tightened or adjusted them since I got them perfect, and between the dampened bar ends and the rubber isolators built into the CRG' themselves, they are erily clear under any conditions.
I have the version 2.0. They are up to version 3.0 now, so you may be able to find the older ones cheaper. I like the old ones better, as they are a bit more retro -- the 3.0 are more styled/streamlined.
Also, I have the lanesplitter version, which I think is worth it. Not only for splitting, but for parking or moving around in garages etc... the bike gets pretty wide with ~3.5" added to each side.