Saddle for Wide backs and high withered horse

I am currently riding my QH in a wide tree collegiate saddle. It fits him really good through the shoulders, but I kinda cuts low over his wither, and I am afraid its rubbing. I'm looking for something that still comes in a wide, but also has a high wither. I am in the $400-$500 range and am thinking about some of the used wintec isabells or pros on ebay. Anybody know how these fit high withered horses? Also, any thoughts on thorowgood?

Look for something with a partially cutback pommel. The Isabell has a cutback pommel, so that should work well for him. Older Passier and Kieffers are a good option. The Kieffer trees can be adjusted by a qualified saddle fitter, and Passiers fit a really wide range of horses.