I've shot Mamiya 7 on Maui for weddings, and it can indeed be a big pain in the rear. Leica is the only camera to get the most from the 135 format. Nothing else compares. I've dropped 135 altogether, and shoot with Rollei TLRs and recently added a Mamiya M645 Pro (will be adding an M654 TL body very soon) setup as a replacement for the 135.
You may want to consider the 645 series as it is significantly cheaper than the 7, and just as good. Plus you will have 15 shots on a roll, which you may find easier to go through. As usual, KEH is the place.