These are actual bikes designed for Clydes and Athenas by someone who knows what he is doing (Lennard Zinn):
https://bikeclydesdale.com
They are not super cheap bikes but they are reliable and durable bikes that aren't boat anchors but can handle big and tall.
The Rein: can handle up to 450lbs can run 40mm tires and has a nice reliable 1x11 drivetrain and handbuilt wheels which are quite important for a big and tall rider. It is 3450 for the model with Steel fork and looks to be quite a great option for upgrading over time. Certainly would top my list if I was tall and had a little extra to love (not that tall). Yes out of the budget potentially but seemingly one of the few options listed that is actually rated for Clydes. Most of the stuff will probably need a bit of modification to a lot of modification to be a reliable bike over time.