HI, There are a few custom builders in the business...A full blown custom job will run about $3000 and up. Look at Millennium Custom
www.mcguns.com
or Fusion (on 1911 site)
I have guns built by both and they do a complete Custom 1911 or 2011.
You can also look at Wilson or Nighthawk....
Have fun with your build and they are taking about a year at this point.
You must consider hammer, trigger, barrel (carry or competition) thumb safety (or two) MSH with or without magwell, grip safety, sights, and final finish (Fail-Zero, Ion-Bond, Blue, Blue-black, chrome, etc. Grips Regular or thin, G-10 or wood, checkered or not or part. Grip checkering, press checks front & back.
Gary