Difficult to recommend you something.
- Do you want new gear or can it be used?
- Do you insist on having "Leica" on the body?
- Do you mind mixing lenses and manufacturers from different makers?
The ZM is an excellent modern body, with the option of automatic exposure and what's probably the best finder in the rangefinder world. There's been a lot of discussion about its "build quality" with Leica people chiming in how it isn't a proper camera if you can't hammer 12-inch nails into a wooden plank with it (not that I've ever seen somebody do that with a Leica). Or how its battery dependence is crippling the camera, while it uses a kind of battery that is extremely small and extremely easy to get everywhere in the world. This is the kind of discussion best left ignored. I think the ZM is a good idea. The obvious alternative would be a used Leica M6; it should cost slightly more than a new ZM if in good shape, but it's comparable in general. No AE on the M6, but for that you get the Leica name on it if that means something to you.
Regarding the lens, a used Leica 35/2 should be more affordable than a new one. However, the Biogon 35/2 is a very good lens enjoying a positively excellent reputation so you can't go wrong with that.
There are lots of other rangefinder bodies with M mount: the whole Leica M series (depending if you want a meter or not, or what kinds of lenses you want to use); the Leica CL (compact); the Konica Hexar RF (motorized, somewhat automatic, nice); and the Cosina/Voigtländer Bessa R[234][AM] series (affordable, good, some unique viewfinder options). And there's lots of lenses in the 35mm range: Zeiss, Leica, Konica, Cosina/Voigtländer, and all sorts of old screwmount lenses from lots of manufacturerers. So if you want choice you can have it, and you can read and write in lots of online discussions without ever taking a choice (or a picture). Personally I'd just check my budget and if the ZI with the Biogon fits it (possibly used) it is a good choice that you're unlikely to regret.
Philipp
