S9 had been released and will ship on June 12th, in 4 days. Trouble is it's crappy, why everyone thinks it's mother's milk, I don't know. Bitmain hasn't released anything of quality and value since S3. Their S5 and S7 have sold well but that doesn't mean jack shit. Oftentimes, their gear goes up in flames if you look at it funny. China-built, China-quality. I hope you buy them and your house goes up in flames. Don't blame me, I told you so.

One thing to remember regarding your "free power". I expect there are limits on it as you mentioned, but furthermore, at a practical level a miner converts electricity to heat. A 1000W miner is just like a 1000W heater. If that is going to impact your living environment in some way, be aware of it. Some miners are also quieter than other, with the general being that the hight the wattage, the louder it is. If you are thinking of putting two S9 miners in a closet, what would it be like if you were to put 3 hair dryers, on full blast, in there round the clock.

Would that be a problem?

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.

Well if want to buy USA gear you need to build a pc and mine eth coin.

If you want to buy from China the s-9 or s-7. From bitmaintech or Avalon 6s from Avalon.

How much free power do you have?

10 kwatts or 2 kwatts  or more or less.

The s-9 uses 1.4 kwatts per hour.
The s-7 uses 1.3 kwatts per hour
The Avalon 6 uses 1100 watts per hour.

I have a few used s-7 s and Avalon 6s if you want.