RE: Whats the difference in SA, DA, and DAO
DAO are going to have the heaviest sloppiest trigger pulls on average...
On a DA/SA your first trigger pull is going to be heavy/sloppy but the following trigger pulls will be better.
A SA is going to have the best trigger pulls of all.
Bassically this has to do with the DA having to both "cock" the hammer and release it where the SA's only have to release the hammer... Overly simplified but maybe that will help.
Go with a 1911... IMHO best pistol out there...