Cervelo and Felt have 61 cm frames. Most other are smaller. Softride has XL which includes the 61cm range (but, inexplicably, the beam is only rated to 200 lbs).
Any other big stock frames? Bigger stock frames?
Yes, I know that one can get a large frame custom made.
One thing to remember with the Softride beams (the classic beams anyway) is that the break strength is WELL above the rated rider weight. I’ve got beams on my bikes that are in the 12 year old range, and no problems. I have the lighter weight beams, and rode them with no ill effects when I weighed 200… And I think the rider rating on those is 140. I’m at 165 right now. Unless you get over, say, 700 lbs, you don’t have to worry about breaking the beam.
You should check out Guru’s.
I know your talking about stock frames but if you look on Elite’s website they made a big ass frame for a dude. I think the dude was like 20 feet tall or something.
Trek 
.
His seat is too high.