Looks Good man!

What are you doing with those 4 computers that you run 650 watts each?  Playing videogames on max with dual video cards??

Avalon 6 has a group buy it looks like currently that might be worth looking at if stuck on 110/120.   But your right if they are able to power the S7 it is cheaper as far as hash currently.

I think he needs to figure out the wattage like you said though. Unless his line is 220/240 I think one modern miner will use most of his "2 power outlets but are on the same power line"

WOW that a goods a deal free electricity from 9PM to 6AM, where country you live ?

My advice you can buy 1 antminer s7 and if from 1 antminer s7 you get a lot bitcoin, buy 1 again.

It also depends on what your electric costs the rest of the day. If you only mine for those 9 free hours it'll take a lot of your time (having to start/stop the miner each day, unless you script it) plus youre only mining 38% of a day. You should figure out what it would cost to run a miner 24 hours, including the 9 free hours. It might still be profitable. Or look at buying older hardware for cheap/free and run that only during the free hours.

The problem might become that if you start a big farm of old (free) hardware the power company will realize it and start charging you for the "excessive" use.

the next step would be to see how many wattage this place can deliver, and how much is your investment

then you can go ahead and buy a s7, don't bother with other asic, as they require more wattage, which mean more psu