Caspian makes great receivers if you just want the receiver and nothing else. If you are looking for a complete 1911 that you can modify a little at a time, then look at Springfield Armory. Honestly, the days of building a nice 1911 for less than you can buy one are long gone.
Last year, a friend gave me all the parts from a Colt Officers Model, except the frame. I bought a Caspian frame with intentions of building my own. When the frame arrived, I realized that I'd bitten off more than I could chew.
I contacted a retired armorer/gunsmith from my old department and had him put together a half breed Colt/Caspian. I tested it at 15 yards, using an NRA bulseye target. The first five rounds, fired off hand, were in the "X" or ten ring. The second string of five was a repeat of the first.
My buddy said that Caspian makes the best frames for what I wanted,
This is probably a bad word with most of you guys but, the Essex SS Frames are pretty good. They're considered a Class A frame by Wilson Combat which puts it in the same class as their own frame and Colt. I have one that I built 16 years ago and it's still tight, no stretched holes, nothing out of spec. No alignment needed for anythng when I built it and it readily accepted all brands of parts with minimal fitting.