If that were me, I'd look for a Summicron - an excellent, all-purpose lens. Then I'd add a 35mm, or wider, at some point.

The Elmars are decent lenses, but if you're going to get a Leica M, you might as well get the best lenses that you can afford. Leica produced a new line of Summarits a few years ago, and I'd probably seek out one of these in both the wide angle and short telephoto lengths.