It's easy to adapt a C body to accept an M head but not the other way around. For what it's worth, your SW02 will work fine with the M3.
The C2 is a perfect fit for those parts and the C3 would allow you the same battery capacity as the M3. You could also check in the Custom and Modified Flashlights sub-forum for some custom made bodies that could accept 3 cells and would be compatible with your parts.