Sorry for the late reply.
Did you ever get your new mainsail? If so, what did you go with?
We went with Doyle StackPack. Bought it from their loft in Marblehead, MA, but it was made by their shop in Honduras.
How do you adjust your mainsail luff tension given that the boom is free floating in the mast track and downward pressure is largely controlled by the mainsheet?
Not well, I'm still working it. The halyard seems to bind before I have the tension I want. Maybe my topping lift block is in the way, maybe my halyard splice is too long and binding in its block. I'm going to look at both, but might end up lowering the boom (yuck, yuck) if I can.
Life has been crazy and I haven't had the time to tweak (barely time to sail).
The StackPack was a bear to set up, but works really well.
I paid a lot (IMHO) but Doyle has a good rep.
Doyle DuraSail w/ StackPack & LazyJacks
2 full battens/2 partial
Sail numbers & Bristol insignia