my issue with doublestack 1911s in 9mm, 38 super and other similarly sized cartridge is most of them are built in a frame made to hold a double column 45acp mag so theyre going to be excessively wide.. if i were to do it and funds were unlimited id base it on a caspian double stack frame which is thinner because instead of being designed around a double column 45acp mag, it was designed around a double column 38 super mag, so for a 9mm it will be slimmer, lighter, etc
this would of course require you to build the pistol yourself, but the frame should be compatible with any 1911 slide assembly