I did know where to ask this one..
But a few years ago I painted a Boat and the guy had a really nice cover.. It was really thick and had header covers built in.. The guy said it came with the boat and hasnt seen one like it before.. Does anyone know where I can find one of these??
Custom built my friend, get in touch with one of the marinas near a harbor and they should be able to point you in the expensive...I mean right direction...

Be sure to specify "Marine Sunbrella" there are numerous different grades of canvas, marine grade being the most durable and colorfast....
I am a cheap SOB, I buy the universal fit Taylor covers for like $125 and have the old man customize them, the covers are cheaper than just the materials to make a custom...

GT