Would like to buy UV and polarizer from either Heliopan or B+W.
Is this a good choice?
If yes, could anyone give partnumbers?
If no, what other choice do I have?

I got a lot of flaring with my 43mm Heliopan UV, on my MX300. The Leica filters have a different pitch, which can't screw on to the Pana. I suggest getting a UV and polarizer from: Tiffen, Cokin, Hoya, and Vanguard. These are good filters and they are inexpensive. I have filters from all these companies, and I'm happy with them. I especially like Cokin filters---I have several for my MX.

I have a Tiffen UV filter on my camera, and yes it does make more flare. The only suggestion I can give, is keep it clean, when it's all smugged up, and you have something with light coming in from behind a subject, it doesn't look good at all, it has like a bad foggy look....

With my Cokin UV and Cokin circular polarizer, I get no flaring.

http://www.cokin.fr