In much need of a better solution to scale our project. (multiple gateways using 4G data sims)

Hello there!
My first Reddit post comes at a time of much head scratching. Currently we are working on a project which requires each of our virtual machines to have a different IP(ten total). We have several data sims running in USB modems plugged into multiple TP-Link MR3020 which are then connected to a switch. On the vms which run Windows10 we specify the IP of the router/sim we wish to use and that all works fine.

THE PROBLEM
We want to have more internet connections but also want to avoid the cumbersome hardware which will come with it. I have been searching for a solutions and would like something like this. However we already have something similar and it requires 3rd party software and a whole lot of configuring and thats just to use VOIP. Ideally we want each sim in the modem to have its own ip so we can just specify the gateway for vm pointing them to a different sim each time.

THE QUESTION(S)
Does this product exist out there and if so can you point me to it?
If the product does not exist can somebody make one for me or point me in the direction of someone who can? (I will pay you good money not the bad stuff...)