What you describe is exactly my situation, Size 12 boots. 150lbs.
But, the difference between you & I is I want a big board. I've shopped for low-profile boots but haven't found much. Some years I've even crammed my feet into a smaller size boot and cut some liner out. Painfully.
The only solution I've found is to get a propper boot-fit. Wear comfortable boots, and then make the rest of your gear adapt to your boots. That means bite the bullet and find a really wide waisted board.