Originally posted by cpceter Do I really need...
You can stop right there. The answer to any question that starts with those four words is always "no."
Would you be happier with A lenses? Maybe. I prefer them, since the only thing they're missing compared to a modern lens is autofocus. With Av mode, my preferred mode of operation, M lenses do not work as intended. As JinDesu said, you can only use them wide-open if you want the camera to keep metering on the fly. M lenses aren't suitable if, say, you want to shoot a rapid burst of shots tracking a subject through changing light conditions. You say you're not planning on action shots, but sometimes action happens without you planning on it.
M42 lenses are easier to use than M lenses, IMO, since the camera doesn't hold the aperture open. When you stop down, it stays that way all the time, and the camera meters accordingly. The really old lenses with preset apertures are the easiest of all, since you can quickly switch back-and-forth between wide-open and your chosen aperture.