Either way, any revolver in .45 ACP is going to be on a large frame and probably close to 40 something ounces. Fine for a primary sidearm, but it's likely will be just as heavy as what you're carrying.
I'd look for a .38 or .357 magnum revolver or go with a compact .45 ACP auto, like an Springfield XDS. Or possibly a scandium frame 325 revolver, still large in it's dimensions, though.