i'm a bit of a renegade...but what i would do is just make the butterfly as comfortable as possible in my DT and hope for the best. either that, or return him.
i would not waste money on a UV
i don't know about inline heaters. never used one.
poly pads? what are they? those fluval foam filters? i'm guessing they work fine on a fluval.
did you want some filter floss for your sump?