Which router to choose 3g with routing?

Question

Computer networks

Good afternoon.
I beg you to help with choosing a router with 3g / 4g
Task: It is necessary to organize a backup channel over the mobile Internet. Location in the city, with communication there are no problems. In the presence of a sim card with static.
Requirements:
1. built-in support for a sim card and connection to the Internet through it
2. at least 1 LAN
3. it is desirable to have dhcp
4. the possibility of port forwarding
5. price ... 4000 ???
Result: Devices from outside should reach the internal PCs on certain (non-standard) ports.
Or, as an alternative, a 3g whistle that can bridge. All those tested by me give out their internal ip (192.168) to the router, and the ports, respectively, go to the forest.
Yamarket did not help much, because much remains unanswered.

Answer 1

Mikrotik