Looks promising, though I thought it was gospel not to use SATA power because of the cards drawing more power than it's rated to handle?
I have connected both Biostar SATA connectors directly to one PSU like is recomanded on Biostar site: http://www.biostar.com.tw/app/en/event/crypto_mining/page4.htm. Also the risers and the GPU are connected to PSU with other two cables. I don't think it's something wrong... I hope

I think you'll be ok. I also use the HX1000i and HX1200i but the risers are fed from a single 4xSATA adapter that goes to the 8pin type3 connector on the PSU. I think the cards take most of their power from the 2x8pin conectors and almost none from the risers.
I have a question tough: were do you get the long cables for the psu ? I don't seem to find them. Are they custom made ?