Flowering and veg cycles are completely up to the grower preference, you can induce flowering in a rooted one inch clone if you want or you could grow a sativa dominant plant 14 feet tall before you induce flowering its up to you... What it really comes down to is how much time you have to wait for the plant to grow big, and how much room you have for bigger plants (obviosly while practicing "supercropping" techniques in veg such as topping, bending,bansai-ing, FIMing, lollipoping ect...will multiply your yield as many times as your patience and percistance allows. Hygrohybrid has good advice and vids on youtube) Just one thing though you absolutly need a seperate veg and flower rooms to maintain a perpetual harvest and get enough yield to make paying the light bill worth your wile. As far as cloning taking a clone from a vegitative plant is the only way to go in my opinion because you take a clone from a flowering plant you risk waiting up to 2 months for it to revert back to vegitative growth and in the long run will cost you extra nutrients, inefficiently used space in your grow show, and money to veg it extra long before your desired size. Also another important side note you can grow them bushy and wide rather than tall... I will post a pic of my finished product of suppercropping plant. The plant in this pic yielded over a pound after it was dry and cured! it was only 20 inches tall, but almost 4 feet wide! you can manipulate these plants to grow however you want! I took this Liberty haze plant when it was 2 ft tall and slowly and carefully bent the top branch where it met the branch below it and in the opposite direction and where there is a gap between main branches bend the horizontal smaller branches that are coming off the main branches into the open space where it will get more light ( you can even convince the plant to make side branches by carefully bending the branch just above a new node, if you bend it until it either pops or can be completly bend to the point it can touch itself then the new node below it recieves hormones telling it that it is now the new "top" of this branch!) check the bends daily tape over any splits that happen, its ok if your new bends leave the leaves upside down it will revert back to facing upwards in a little as an hour! every 5 days bend some more creating a big round bush, also apply the other supercropping techniques listed above (except basai in this method)you can top again every 7-10 days or so, skys the limit. Cannabis plants are like hoes the more you smack them around the more they want to please you!