Hello, with buying a mining rig like this be sure you're checking all the reviews and looking at specifications from other miners to see the total potential of each rig.

If you have got the funds to purchase, high-end rigs, I would personally recommend looking at https://shop.bitmain.com/ a very trusted service in the mining community. You can also use services such as Amazon that are selling pre-used bitmain rigs.

Another suggestion is that you could initially build a rig yourself, purchase a rack/cabinet unit for your own rig can also be found via eBay, or Amazon.