Easy to do.... just drill & tap the slide, mount the rail, and hang whatever you want on it.
However..... you just changed the mass of the slide, so you'll need to monkey with a bunch of recoil springs until you find one that works. Also, the slide banging back & forth will trash almost anything you mount on it..... even with a recoil buffer.
I have seen some that mount "under the chin".... not sure if they were add-ons or if they were an integral part of the frame.
To each his own..... I'd consider it a crime to put a rail on a 1911..... save it for the AR. Or, be a mall ninja and hang everything but the kitchen sink on a short-barrel pump shotgun with a folding stock and a pistol-grip forearm.
All the cool kids have dustcover M1913 rails these days, for weaponlights and so forth.
New 1911s seem to come in both flavors - Kimber offers many models both ways. Same with Springfield.
If your Kimber lacks one at present, poke around a bit - there are quite a few aftermarket ones. Chances are you'll have to drill and tap the dustcover on your gun. Dawson precision makes a proprietary rail (i.e. you'll need a light-specific adapter). Novak makes a proper M1913 rail.