Whew... TALL...
I think there have been some people that have been happy with road bikes up to around 250 lbs... so don't completely exclude them. Especially if you can find a good road bike with > 62cm (hopefully made for the tall, strong riders). Get good strong wheels, perhaps even custom wheels with 32 or 36 spokes.
As @
TriBiker19 suggests, good vintage steel bikes show up in taller sizes from time to time, depending no where you look, the size of your community, and whether you wish to get a bike or components shipped.
You might also look at some of the cyclocross bikes in tall sizes. They should be made strong with reasonable "road" features. Some are even made out of carbon fiber, but designed to take some abuse.