Sail Area / Displacement is the ratio you want to be looking at when looking at different boats compared with yours. As the sail area decreases or the dispalcement increases the boat will become somewhat less prone to healing. We have an Island Packet 35 which at 18,000 displacement and a full keel does heal less than other boats I have owned, however we still see 10-15 degrees of heel in 15 knots of breeze.
You don't mention why the heeling is an issue, but with your current boat, a reefed main, a smaller headsail, eased traveler, tightened vang will all help to reduce your heeling. You will likely be surprised at how little performance you loose with a reefed main and a 100% headsail vs the larger overlaping headsail shown in your photo, while at the same time greatly reducing the heeling of the boat. Just trying to point out there may be a simpler way to achieve your goal.