Mobile 4G Setup

I'm looking to build a custom high quality mobile setup for a large semi truck. I have my mind set on the Quectel EM20-G CAT20 which is a 4x4 mimo modem

One of the items I'm having trouble finding is a high quality omni 4x4 mimo antenna. I would like to have one which is designed from the ground up as a 4x4

Would be great if someone could point me in the right direction