586 l comp

Hello. New here and I had a question. I was offered a 586-l comp but I prefer a 4 inch barrel. I was wondering comparison of the ported 3 inch to 586 4 inch. Felt recoil, muzzle rise etc. as I am a bit recoil sensative due to hand issues. I was even thinking of porting my 4 inch for this reason. Smith and Wesson said a barrel swap to 4 inch on the 586 l comp is not possible. True? So in the end, as I would like a blued seven rounder, deciding between the 586- l comp (a bit lighter) or having a cylinder swap on a 586. As an original 586 with 7 rounds is like finding a needle in a haystack. Thanks for any advice.