ever heard of LST(low stress training) or SCROG(screen of green) before?
you don't have to make something like this of course,just get the idea.
there are basically many forms of cropping,but IMO these two are more suitable for growth control.
Some say that Autos don't react well to scrog,i don't see a reason why it wouldn't work,but I've never tried to scrog any autos so i cant tell you for fact.
In that case LST will be the next choice,but the growth control with LST is only to a curtain degree...
I personally would advice you,cuz of your limited space,to grow photo plants,unlike autos,you can flower them whenever you feel like it,and thus have much more control over growth,Autos,best left alone,and let grow wild.