new hps lights- ready to flower- need advice!

Hello...
I am on my first indoor go-round with 3 plants. Vegetation began about 2 months ago under a florescent lamp and the plants seem healthy but not prime.. so I ordered a 400hps and metal halide lamp set up and recieved it today.
So my questions are: should I continue in vegetation with the mh bulb for a while, then switch over to the hps and 12/12 cycle? All 3 plants are between 1.5 and 2 feet tall... so I think I could be ready to flower. But if using the mh bulb for a week or so would improve the Quality of the plants then I was thinking about doing that and topping the plants or something (so they dont end up enormous)

Any help would be greatly appreciated! Like I said this is my first attempt... I can post pics tomm if needed... or any other information

It really depends on your grow space friend. Bear in mind that your plants will between double and triple in size during flowering. If height or time isn't a restriction then there is no reason not to leave it to veg longer. Indeed the longer you leave it in veg, the bigger the plant will be, the more budding sites it'll have and ultimately, the more you will yield. If you do decide to top to restrict the height a bit, then make sure you allow the plant the recover for 1 week before switching onto 12/12.

Okay, so if I top and switch to 12/12 cycle in a week or so, the plants will not grow as tall as if I were to switch to 12/12 now and leave them as is? My grow space is in a closet, so I musn't allow them to continue in veg. state much more, and I only purchased one 400w hps light/ballast for the set up. So far I have done little pruning and trimming because to be frank I dont want to cause harm...

On a different note, I was reading about making a cutting for a clone and was confused... Im still unsure of the sex of the plants but I am thinking 2 of the 3 are female. If I want to continue the females after this flowering stage, must I make a cutting and start anew? Your help is greatly appreciated

Start immediately.

2feet tall?flower.

Balls. Okay looks like its flower-time. Tonight i'll get the new light set up and will post some pics tomorrow
Does anyone have advice about cutting for a clone? Is this necessary if I want to continue the plant's life after the first round of flowering and harvesting?