Colt, Ruger, Kimber, SIG, Springfield, Rock Island, Giesan were all the leaders in the 1911 frame. Yes their are others. Then you have the high end hand crafted production line, Wilsom, Ed Brown, Baer. The you have the new manufacturers, Staccato (new Name- Old manuf.) and others.
This is by no means an all-encompassing list of 1911 manufacturers.There are way too many custom manufacturers to list them all.Instead, I’ve compiled a list of the most common 1911 makers and their current offerings.
www.thefirearmblog.com
One needs to determine the general use or specific application, That may help in determining the caliber desired as well as the size. The 1911 frame is one of the most modified firearm platform. It length of service in long and one can change to meet the desired intent.
Function, Reliability are key features. All 1911's are not created equal. They are endowed by their manufacturer with certain properties. One can purchase parts and assembly or purchase as a complete unit ready to go right out of the box.
One need to conduct their research and find what works form them. As questions, ask friends ask at the range. Firearms people are typically more than happy to discuss their wares.