I would recommend all three. I have grown the bbka and expect 150 gram plants and up to 200 with think different and up to 300 with the auto ultimate. I have not grown the ultimate yet but have seen 300 gram plants. I have grown 300 gram auto extremes. If growing two go with think different and black berry kush auto. Think different is a smashing sativa high IMO and BBKA is more INDICA stone. Think different is in a league of its own. But to get huge plants I run allot of light and feed Advanced nutrients ph perfect line, I run sensi a/b grow and bloom, voo doo, sensizym, b52 bud candy, rhino skin, bud factor X, big bud, over drive,nirvana and tarantula, planet green cal mag,. I am a firm believer in overkill with exhaust I have a 5 foot by 5 foot tent I use a 8 inch inline fan and charcoal filter to match. I have passive ventilation plus a 6 inch inline forcing air into my grow room. I use 1420 true watts of led three different spectrum's. I use soil less mix pro mix HP HIGH POROSITY or sunshine mix #4 perfect soil less mix for growing huge ass plants and airpots at least 3 gallons but I use mostly 5 gallon airpots. Any questions ask away. You get out what you put in that is a fact. Oh yea I have never measured my ecu ppm or ph levels ever no pens no ph buffers they are just not needed. WEll I rambled I hope this helps someone grow huge ass plants