Dear Clydesdale Anonymous
While I am rapidly on my way to joining you there is a steel tubing that is excellent for the larger frame and has the side effect of being very good/excellent compared to other steel frames for the larger weight.
Look for a Columbus MAX OR framed bike, often found easily in a Kona Explosif from 1995 to 1997. Can be found elsewhere but you don't see them often and from earlier years.
Anyways, give it a try.