When I smoke fish I apply cold smoke. Then I can bring the fish up to temp without over drying it. All it takes is a pellet smoker like the A-Maze-N tube and a kettle grill or any smoker etc. Such smoke delivery devices do not generate enough heat to cook and dry the fish. You can bring the fish up to temp in foil to better preserve the moisture and texture.
I smoked salmon for salmon Mi Cuit (yeah, some French chef may slap me). I just want a hint of smoke on the Mi Cuit prepared salmon. It can not be smoked in a temp above 80 degrees. In fact, the fish is placed on a completely clean grill (I use cooling racks) and the fish is ice water cold and never gets warm at all. Salmon Mi Cuit is finished to a temp of 104 degrees.
No more dry smoked fish. The difference will set you apart.