is there a read a.k.a guide on what this bare minimum is?
Ive played with the calculators and with my local kilowatt hour at .14 its calculating a $2800 profit annually per S7. Of course thats a "perfect world" scenario and in no way guarantees anything, but still keeps me interested and wanting to join the "rat race" for bitcoins.
But before spending actually $ on hardware, what do I need to know?
No idea where you get a $2800 annual profit per miner. At .14/KWh you're playing a losing game. Every 2 weeks difficulty rises and that lowers profit even more.