I would customize it. BUT I would do so in such a fashion so that it could be returned to it's original configuration. Not too hard to do, just make sure your gunsmith understands that you want the parts fitted to the gun and you want the original factory parts back. About the only thing I've done to my 2 older Colts (a 1991A1 Commander and a stainless Officer's ACP) is put in Wilson's drop-in beavertail and, on the Officer's ACP, a S&A magwell. I still have all the parts.
My older Government Model has been extensively modified, largely b/c the frame had a flaw from the factory that I didn't notice when I bought the gun. I've had the trigger redone, a beavertail gripsafety put in, Bomar sights, and a an extended safety.