You can put two winches on each side, if you need to. I'd avoid "stoppers" because of the friction, but there are ways to solve that. You could have a winch only on one side, but have cam cleats on both sides. A self-tailer which you might or might not use on one and the other with just a cam cleat or stopper.

Your main is analogous to a J/35 or j/105. You can balance the multi-part.

The traveler can still be as you have it. The main's lines would just lead above it to the starboard and port coaming areas (inside the cockpit).