Originally I was just going to stretch the the boat and raise the deck.

Teddy:
I agree with your original idea, if modifications are required.
Widening a 'surfski'-derived hull seems to me to be missing the point a bit. I'm assuming that you are interested in this boat because you want something fast, to be paddled with a high angle paddle style. Making the boat any wider defeats the whole purpose. Panthera is not a 'tippy' boat IMO withthe designed width, and my paddling skills are definitely not more than 'intermediate'. It feels nothing like my Think EZE surfski, which is a 'stable' (sic) surfski marketed to beginners.

About foot clearance: This can depend on what type of footpegs or footboard you are going to use. If planning a footboard, your toes will be near the mid-line, where the deck is highest. If using 'gas-pedal'-style commercial footpegs at the sides, you may feel the need to raise the deck. You'll need fairly compact footwear when operating the rudder controls in either case, IMO.