I'm seriously considering getting another 5.5" Remington and another spare cylinder, and some more lubed wads while I'm at it.
I'd like to convert one to .45 Colt, but I already have an EAA Big Bore Bounty Hunter in .45 Colt, and the conversion cylinder would pretty much pay for another BP revolver. Perhaps the Target Remington, or the Remington Police .36.
Or maybe an 1860 Colt (sacrilege, but Junkman01 has gotten to me with his love of the 60 Colt)