MountainSufi ...
A few things to consider. That Cel-fi kit you linked to is designed for a permanent installation on an unmoving object, aka, your house or cabin. The outside antenna is directional, so you would have to be able to hook up and use an RF power meter to aim it. Also, I think 50dB of gain is the max allowed for mobile installations.
Further the device works like most "boosters" do, meaning that they take an existing cell signal and amplify it. There is a limit on how much they can boost the signal without causing feedback, by feeding the amplified signal back into the receiving antenna. There are a variety of ways they control this, one is by making the boosted signal extremely weak. The WeBoost internal antenna is a tiny thing that works best if you rubber band it and your cell phone together. VERY awkward way to use your phone. I ended up turning my phone's Hotspot feature on and connecting to that with my computer for skype/zoom calls.
The other thing to do is to make use of the "dead" zone directly underneath the outside antenna. Meaning positioning the internal antenna right underneath it. Also awkward.
Best way around this is to use the "hotspot" feature by design. Meaning receive cell signal, and broadcast WiFi. Such a device is no longer a "booster" though. The system I am installing now is exactly that... receive cell, transmit wifi. I will be able to use my phone/laptop sitting around the fire having a cold one rather than being trapped inside my camper.
As for antenna wiring, I was using the WeBoost Trucker antenna before. I had that mounted to a section of 80/20 that was mounted to the rear passenger side jack bracket. I could lower it for travel, raise it for parked/work use. I could go from 1 bar to 3 bars using that setup. And the wire was anchored inside the camper, penetrated to the outside in the wooden floor pack, and then had enough slack to be able to raise all the way up. When down, the wire tucked into the space between the camper and the truck bed.
