We do not recommend any particular manufacturer. However, there are few good pieces of advice based on best sector practices and experiences which we can give you:
- Be wary of suspiciously good deals of hashrate/price and unknown companies.
- Consider the hardware's power consumption and power bills you have to pay.
- Later shipping dates usually mean lower than currently estimated profit because of the rising mining difficulty.
For a comparison of ASIC miners we recommend asicminervalue.com. There are dozens of devices listed with complete specifications and profit estimates. Don't forget to check which algorithm the selected device is made for and which coins can be mined with it.