Anex, I'v used most of the cameras you mentioned - G1, GF1, EP1, X100, M8, M9 as well as LX5, Nikon 1 V1 etc
Anyway, for the application you're talking about, I would imagine that sensor size shouldn't be important as long as you have a choice of focal lengths and the thing is in your budget, in which case I'd be looking at whatever the cheapest Olympus Pen or Lumix is with the optional viewfinder
I'm not sure why people criticize the VF on the X100 by the way, you can use it in 2 modes - purely optical with a HUD showing focus information etc or as a true WYSIWYG EVF and you can also use live view on the back screen so its certainly no worse than any of the others in this respect. I love the Optical VF mode - brilliantly clear for framing.