Prerequisites for SAP Netweaver Gateway

Hi Experts,

we are planing to implement SAP Fiori applications in my company. for this I need to prepare the prerequisites for sap netweaver gateway.

I read few forms but I am not get clear picture on this kindly clear my below queries..

1. which is the latest version in sap netweaver gateway.?

2. what are the hardware components required .?

3. do we have to buy separate license for this server. ?

4. if we buy how many user accounts we will get.?

thank you.