Leicesturm put it better than I could. V-brakes will definitely make you happy. Set up is everything. Your local bike shop can sell you an extra tall stem. It's worth a shot before buying a new bike. If your wheels taco'd, it's because either you had some sort of collision or they were lousy wheels to begin with. Some people put astonishingly big loads on 700c wheels, and it is not an inherently weak size.