I would look at some of the B/Vertigo as well (also a Horze line)
I recently got a pair of these breeches: https://www.doversaddlery.com/ds-premium-fs/p/X1-350393/
I know they’re women’s, but they are surprisingly loose in the fit and don’t feel restrictive at all. Nice material with a technical feel. Breathable and light. Silicone FS. They have fake pockets in the back.
I am also one who insists on a full seat, and it really narrows your choices in the US - I don’t know why the knee patch are so popular here! If you’re willing to go over budget: Cavallo, Pikeur, Cavalleria Toscana, Animo, Samshield, Horse Pilot, Kingsland, Equiline, Euro Star, Schockemöhle, etc. come to mind. I’ll tell you–it’s a good investment. If you buy good quality, you won’t have to buy too many more down the line.
Otherwise: I’d direct you to some of the European sites. EquiShop, Equizone Online, Reitsport Fundis, RideAway, Calevo, JustRiding come to mind. I really mostly buy in / from Europe – it’s just easier and cheaper.
You may want to check out the VTO stands at events-- also, Land Rover Kentucky, etc. tend to have some excellent deals on some of the European brands.
Good luck