What devices should I get to setup LoRa Getway

Hi. I am new to this technology. I will start to setup a LoRa Getway, but I do not know what devices I should get. I have got a Raspberry Pi and I am thinking to buy a HAT RAK833 or RAK831. Firstly is there a difference with these two? And for RAK833 I need a Pi Supply to setup on Raspberry Pi. So which antenna I should buy and do I need additional cables such as jumpers etc.

I really appreciate if you guys could help me. Thanks