I have one that's 21mm/28mm from Ricoh that's nice, mostly that goes with the m9 for the 21MM SEM though.
I think there's a flatter (or smaller) 28mm available, I'd look for that.
I've gotten to just slipping the Coolpix in my shirt pocket, foregoing the OVF. Not my preferred way of shooting, but can't beat the portability for an APS-C camera (besides the Ricoh GR).
You might end up doing just that, so just get the camera first and see how you get along with it.