I have pretty much the EXACT same proportions... 6'3", 215-220, and I don't find my size in Big and Tall either. Once I've found a brand that works in a line that works for cycling clothes, I just stick to that.
I end up going to whichever bike shop has the specific thing I'm looking for, there are plenty of them, some good some bad. I do get most stuff over this series of tubes here, once I know what I want at least, and have bought from clearance whenever possible either on the internet or in brick and mortar.
If you have an option besides a place where people are ******y, go there. Otherwise, you guys are pretty much stuck with each other.