I have basic cans on my sloped family room ceiling -- maybe a 30 degree pitch, and we did the Cree retrofit kit in them as well as the one on a flat ceiling. Why not use the same ones? Are they the eyeball type? We have one of those over the fireplace to light a picture. We replaced it with a standard LED bulb (not sure which one it was but under $20). It does leave some space around it that I might not like in the room itself, but since it is pointed towards a wall, it isn't a problem until we find something better.

I was stuck on trying to use the CR6 lamps with integrated trim. But since the trim is integrated the only way to use the would be to have the light 105/75 degrees (rather than 90) to the floor. I found an example where something similar was done
https://www.houzz.com/discussions/are-you-using-recessed-lights-specified-dsvw-vd~58981-you-using-recessed-lights-specified-for---

but they had two matching side plus the large hanging light in the middle to balance it out. I'm not sure if my room will look right with only the one vaulted side. But the slant of the ceiling is not strong, so maybe I am over thinking this.

I just found these regressed eyeball trims
http://www.amazon.com/Cooper-Lighting-420W-Regressed-Eyeball/dp/B000JFKUQ0

they look cleaner that the old style that sticks out which I did want to avoid. The LED BR30 lamp is not as efficient or long lasting as the CR6.