4g modem / router recommendation

Im looking for recommendations for a 4g mobil router or modem . I dont need wifi wired is fine , has a removable antenna as to use an outdoor antenna able to use a vpn . I don't need a lot of power as its for an iot device . 12v dc power would be ideal but not a required . I was looking at the gl-inet collie but sounds like its running modified openwrt ? Otherwise its a good candidate. Open to other options .

4g USB module?

ZTE MF286_, I belive D is the fastest one of all the versions out there.

I do have a router i could use if it supports an externlal antenna .