GOIP Telephone Network Setup

Hello,
I need to setup a business telephone for me.
1. A goip with telephone SIM cards for Calls and 4G LTE Connection.
2. A PC that can connect to internet via each 4G LTE SIM Card
3. A Phone that can make or receive calls via each SIM Card

I already have that GOIP Gateway but dont know how to setup the rest.
Please see attached for more details.

I look for some experts who can help setting up everything:
GOIP configuration, Hardware recommendations etc.