A shorter shaft will also help. I am 5'11" and do a lot of paddling at 208 or 209 cm, but I think I could get used to as short as 206. Shorter lever equals less strain. It is possible i believe to shorten an epic by using heat to remove each blade and then trimming at the ends. I think someone on this forum posted about that recently.
Another thing that will help is modifying your technique. You should try adopting the Oscar Chalupsky stroke. Basically you drop the elbows all the way down to your sides and produce all power and rotation with the legs. It is amazing how much it unloads the shoulders if you do it properly. Boyan at the surfski center in Tarifa paddles that way too and there are lots of videos of him online.
Current Skis: Nelo Vanquish AIR, NK 670 double, NK exrcize, Carbonology Feather, Think Jet, Knysna Sonic X
Former Skis: Epic v10g3, Kai Waa Vega, Epic V12 g2, Epic V12 g1, Epic v10 double, Nelo 550 g2, Fenn Elite S, Custom Kayaks Synergy