Seed Advice?

I'm going to be starting my first grow here shortly. I am setting up my own 6 plant hydro system in a plastic cabinet that measure 30" wide, 20" deep, and 36" tall. The hydro resovoir is about 8" deep and the 250 watt hps is about 7" deep. That means there would be a 18-19" maximim plant height. What type of seed would be best for this small environment. I would prefer a feminized seed with a shorter flowering period. I want the most potent best seeds available! Thanks alot!!! :D

And, yes this is a cross post, but it is relevant in both subforums

go with that low rider...or somthing..i read that thats like a max 12 to 15 inchs and a no flowering period so it will go from seed ot harvest in like 8 weeks with lights fully on...