A little advice on my girls? Should I flower?

Whats up everybody....This is my third time growing, first two were not in the safest most efficient circumstance. I have a current crop of 6 plants....2 chocolopes, & 4 of varying strains.....probably indicas from what I can tell. They are currently finishing their 8th week of veg time @ 20/4, with a 400w HPS, & vary in size from 15-24 inchs. The nodes have started alternating on top growth on all but one, but I think the next growth on the last will alternate. I also have some pre-flowers on a few, which I think are female :thumbsup:. My grow partner & I have been planning to wait two more weeks before switching to 12/12. I read more recently to expect alot of growth after switching cycles, but have read differing info. I worry if they bulk up too much once I flower then they will stink up my whole apartment building :wtf:. If anyone would check out these photos & let me know what you think of the pre-flowers, If I should flower now, & how big you think these beauties might get. Also any smell control methods that dont involve expensive filters?? I have been unsuccessful in even locating these things in my current country of residence. Thanks for any help folks....blaze on.