Coins are at $360, tell me, why on earth are you considering buying more hardware when it'd be a better use of your funds to just purchase BTC instead of mining?
That said, AM's prisma devices. They aren't really rack friendly, but you're not going to beat their pricing anywhere.
Well, currently just getting some feedback so if I
did want to expand, I had a vetted review of this firm from community members (or at least an alternative to this firm if the reviews came in bad). Trust me, I see your point and may sound crazy for wanting to expand with price oscillating sub 500 for a while now & been thinking of just dumping whatever I would have spent into buying coin, but I don't know if I really want to do that.. Worked pretty hard to get near 100 TH thus far, so its not like we are starting from scratch or anything and I do believe in doing my part to secure the network. I have a data center that I already house miners at so it wouldn't be much of a hassle (except the added electric cost) to get them somewhere secure and temp controlled. I will def look into the miners you have recommended and appreciate your feedback!