G,day Dave,

My current project is a surfski using a clc pax 20 hull as the platform. First mod was to raise the sheer by approx. 40 mm to make it similar to a modern surfski. First issue to sort out is the extra width at the catch. This will be sorted out with cutouts at the catch.
If you raise the sheer line or the deck, you may have to address this as well. Depends on how you paddle. Really only an issue if you have a vertical stroke and/or use a wing paddle.
An alternative that you might like to consider and can try out before you commit to anything is repositioning where you place your feet. Racing folk i.e surfskis and K1, have their feet together. sea kayakers have their feet out to the sides. If you are comfortable with the stability of your boat, then the feet together position might be an easy option. If I ever go back to sea kayaks, I expect that I will continue having my feet together. It allows for a very efficient forward stroke and I have never had dead leg/bum issues since crossing over.
i have already buit gas pedal and footplate style rudder controls for my yet to be completed hybris cirrus.
Not sure how this would all work with a no rudder boat but worth a try.
Food for thought, Craig