Forget autos outdoors, unless you are happy to wait 12 weeks and harvest dwarf plants, autos are really only suited to indoor growing and an eighteen hour light schedule to get any performance out of them.
There are plenty of fast flowering photo period plants that will give you 5-10 times as much and in the same time frame of 12 weeks.
Look to plants with a large percentage of Indica genes as they usually finish the earliest. There are some breeders that offer "fast/early version" of their normal strains that are ready 2 weeks earlier than the normal strains, which can be handy if you live in an area with short summers.
Sweet Seeds and Delicious Seeds have fast/early versions that are well stabilized and offer outstanding results in my experience.