I hate when the edit time runs out, oh well will re write this but make it short. I would place the fart fans, two of them over two 4 inch wholes between the two chambers and you will have to do less light proofing and it should draw in some nice air from the bottom holes or louvers. The WW is mostly sativa from what ai remember if you want a version that is mostly Indika then I would go with White Rhino, it is a WW cross. The Grape fruit is nice but it will still stretch when grown from seed and you would probably have to LST them if you want to fit them in that cab if you grew them from clone it would be a different story. If you do a SCROG you will need to do your sexing before you place them under the screen which some people do or get female seeds and hope for the best, if you do go to NL female seeds, they seem to be the best as far as not going hermy on you late into flower.
You really want a small fan in both chambers to help circulate the air, o2, co2 and bi products from the plants along with stem strengthening.
Adieu