Sounds like you have a KILLER space to grow in! Divide the 15x10 room into a veg room and get a perpetual gig going, closet for cuttings. Harvest a couple trees every few months instead of 4 mos. Hell, with a perpet take your pick on a strain cause either way you should still have an ass pile every harvest with about any strain. Obviously some produce more than others but you can also get good results with a very powerful strain that might not produce like another but it may also take twice as long to smoke(depending on what you choose of course). Check out the Med strain sect for info on some and also search similar posts from stinkyattic, "knows her shit" is an understatement.