your going to need a bunch of lights. I would go about this a different way...
first off how much do you want to end up with? cause doing 80-90 plants doesnt mean shit unless you do it correctly, and trying to keep or not keep a canopy on 90 plants is going to be a BITCH. Im guessing you want to end up with a max of 5-6 pounds? just for reference if you did 90 plants and each plant gave you 1 oz of dried bud you would end up with 5.6 pounds. see what im getting at?
are you worried about electricity usage? meaning would you rather have a series of 1000watts or 600watts? 600's will be more efficient but 1000's will bring more dense IMO better buds.
I personally believe that an average-intermediate grower should be able to get 1 pound off of 1 1000watt hps.
Time is an issue so I wouldnt do a scrog even though that will boost your yield by at least 40%. The only thing I can think of left is a SOG, and the problem here is that you are gonna need A LOT MORE THAN 100 plants to get your investment and profit where you want them. Growing industrially is radically different than most of the stuff on here.
here is what i would do.
get 4 1000watt lights. get switchable ones here is a link for cheap ones (they even come with a bulb).
when you start flowering have 3 HPs and 1 MH then towards the end when you flush have 3 MH and 1 HPS.
http://www.hydrowholesale.com/mm5/merchant.mvc?Screen=PROD&Store_Code=hydro&Product_Code=VBX1000&Category_Code=VBHX
make/assemble 4 4x4 foot screens (this is gonna be a scrog, even though that is not the method I choose)
put 4 plants under each screen for a total of 16 plants.
you should get AT LEAST a pound off of each screen.
this leaves you in a really good situation, you have less than 20 plants if you happen to get busted AND your still averaging 4 pounds off every grow. Also should you need to abandon you only have 4 lights to deal with (I WOULD GET COOL TUBES BY THE WAY.)
as far as strain goes get a heavy producing indica, your choice.
after all of that I would NOT suggest going through with this. I have done big migrating grows like this and it is a VERY hectic lifestyle with LOTS of paranoia. my last one got stolen