First mining rig w/ Asus Prime Z270-A 6 GTX 1070 FTW Gaming ACX 3.0

[petcuiulian880]

Hello everyone! I am sorry if I am not posting in the right section! I am starting now with my first rig (I know, it might just be too late) but I want to ask for some advice from you .
I recently (3days ago) ordered 6 gtx 1070 ftw gaming acx 3.0; I dont know what memory would they have but I think and hope that I'll get around 30 MH/s on Ethereum mining.
This would be it:

gpu -gtx 1070 ftw gaming acx 3.0
psu -corsair hx1050
mobo -asus prime z270-a
ram -4gb 2400 ddr4
cpu -intel celeron g3900

I looked up on some profit calculators and it seems like eth is the one to go for with my gpu. Am I right? 
Electricity is 0.14$ where I live, so I think it's a good profit.

I want to ask you guys, an I going to get the investment money back? It might be a stupid question, I know. I presume it would take somewhere around 4 months. Am I right?
Also, on my own PC I have a Asus Maximus VI Hero. It has enough PCIe slots for another 6 gpus. I am wondering if I could run some more gpus on that as well, if I manage to get my investment money back.
Sorry for my bad grammar! 
I will try to reply as fast as possible for you guys! Thanks !

[GaryH]

If you know your hash rates, I recommend going to this site and entering your number of video cards and see what is the most profitable. 

http://whattomine.com/

it will also tell you how many days for ROI, but I don't know if it "knows" when the difficulty increases. 

Also you need to consider if you are mining and holding vs mining and selling/shapeshifting...