Right now, your best choice *IF* you have enough money for 3-4 of them would be the S9 - but IMO wait for the price to come down some.
They'll do the best job of "loading up" your amount of free power the most efficiently - and nobody has announced anything that can top their efficiency by a noticeable degree, much less has anything competative in production RIGHT NOW as a miner.
Thanks for advise. I actually already thought about waiting for the price to come down. I think before I'll gather sufficient information about the rigs the price will come down
