The U.S. Army Model 1911 and Model 1911A1 are single action by definition, the same way a Chevy Corvette is a sports car, not an 18 wheeler. Most clones follow, more or less, the original 1911 SA design.
But a number of pistols which use the basic 1911 type linked dropping barrel locking system also have a DA or DAO capability, like the Llama or the Para-Ordnance LDA.
Jim