Hi,
thanks for the questions, as hardware suggestion I would recommend buying the new Vega 64 or Vega 56 we have two of them in our ring and they perform around 2000Hs each wich is impressive.
Buying pre assembled rigs is always expansive if I were you I would rather build one myself, if you need a shopping list I can provide the full specs of our rigs so you can build one with same results.

There is no minimum hash rate the pool has three different port you can connect your miner to based on the power of you mining equipment:

3333: for mining with browser/weak CPU
5555: for mining with powerful CPU weak GPU
7777: for powerful hardware and mining rigs

Pls let us know your experience with our pool and if you have any suggestion on how to improve it