It is possible, but not very cost effective to do this IMO. In addition to a different barrel, bushing and magazines, you'll need a completely different slide, or machine-work at least, due to the fact that the case heads are very different in diameter. Only then would the extracter grab the case properly.
9mm to 38Super? - yes
45ACP to 38Super? - not practical
I don't have any experience with the 45Super so can't comment on how a RIA would hold up with that. I would suspect that changing it to a custom cartidge will probably NOT increase it's resale value at all.