I use tilapia, shrimp and scallops and sometimes I add clams.
I go to the grocery store to the seafood counter and ask for the stuff I want. I go home and put it in a blender and blend it until it's the texture I want. Put it in a ziplock until frozen and then I chop it up to cubes. It turns out to be about a 1/4 of the cost if I bought it already made.
Thank you sir!