as a newbie to motorcycles and interested in the BMW models?

I'm considering a project motorcylce and have a few BMW cars I do all maint on for the last several years and I have heard good things about the bikes and wanted advice on what might be a good starter BMW bike(i.e. - inexpensive buy, reliable and a good entry bike with parts availability and reasonable pricing.) What models and years to look for and which to stay away from.

Or if too far off topic, can someone direct me to a good BMW bike forum?

Thanks as always,