Most of our customers would choose a 7 mm suit. We offer full suits in 3, 5 and 7 mm. Our largest mens suits, will fit a diver somewhat over 250 lbs. Perhaps this will work for the OP and avoid a custom suit?
These suits are VERY warm and will leak almost zero water if the fit matches the diver reasonably well.
makospearguns.com
These suits are VERY warm and will leak almost zero water if the fit matches the diver reasonably well.

Men's Yamamoto 3D Reef Camo 2 Piece Open Cell Wetsuits
Yamamoto Neoprene is the best and most expensive neoprene in the world. NO OTHER SPEARFISHING WETSUIT HAS MORE STRETCH, COMFORT, WARMTH OR DURABILITY
