I realize you asked for a 45 Colt but I'd really recommend you think about a 44 mag. I've had both, actually have two 44s now and a 357. The 44, to me, is much more versatile and while I realize there are those who preach that the 45 is as good as a 44 with the right loads, I'm not convinced. The only problems I've had with any of the leverguns in any of the popular calibers is they don't feed semi wadcutters well. Some will, most won't. I'm gradually making the change to wide, flat nose bullets.
All can be slicked up, some don't need it. My original 92, long ago converted to .357 from 38-40 (new barrel) is really slick. I just wish it had been a carbine instead of a rifle. The Winchester I had in 45 Colt had an anomaly that wouldn't let you top off the magazine once you'd started shooting. (Even said so in the owner's manual). My early Winchester 44 from the sixties, is kind of weird as it looks like microgroove rifling, doesn't shoot lead well past 1200 fs and is really light. My early Marlin 94, no safety, is the best of the bunch. Both the Winchester and Marlin need .430 or .431 lead to shoot well.
I am a 45 Colt fan from way back but never warmed up to it out of a rifle. Good luck, whichever way you go.