I've read that it is possible to convert Hoyt bows to the Cam and a half system, but generally people are doing that with newer models, so I'm not sure if it would be possible on the Fast Flite limbs or not. If so, you probably would see a drop in draw weight, and it could be pretty expensive.[&:]
It would make sense for you to look into a custom string and cable set for your bow. That would have it stay in tune much longer. (I know what you mean about the cables, as I owned a Superslam Supreme.) Winners Choice, Tailor Made, Wolfden, Stone Mountain, as well as many others make string and cable sets that would solve that problem for you.