small 6" oscillating fan at the bottom of the tank aimed up at an angle across the plants and towards the exhaust.

intake on the lower right corner, exhaust on the upper right diagonal corner... they want to be as far apart from each other as possible.

also, i really would put the exhaust in the very top of the tub rather than on the side... heat rises. take a look at your labeled pic and you will see a couple inches of still area where heat would be trapped and raise the total ambient temp.

as for ScrOG and males... since you have a small area you will want to go from veg to flowering in about 2-3 weeks. this means the plants will be short. with LSTing and topping they can be kept shorter even (both of which should be done IMNHO for ScrOG)... so, you let them show you their sex well before you add the screen.

__________________
wait, let me get this straight... if you fry an egg you can get fucked up?
dissent is the highest form of patriotism