+1 on the Wilson products which are all good to great.
Weboost seems to get variable reviews, but it could just be poor installations.
CellX has the highest amplification, but are locked to a single carrier. Since your visitors could use WiFi calling, I personally wouldn't sweat it.
Locally, the cell tower maps are quite inaccurate, both as to location and signal strength, and at the end of the day, your best signal may be bounced off a hillside and coming from an unanticipated direction.
Just to set expectations; you can turn one bar into four or five, but not zero into something. That's where having signal on your roof is great. To get the best signal, you want your external antenna as far away from your inside antenna as possible given the cable lengths it came with, and you want them pointing opposite directions ideally. (E.g. Rooftop antenna pointing east to the city, inside pointing west.) That arrangement lets the amplifier turn itself up to the maximum power, and not be limited by feedback, like someone with a microphone stepping in front of a speaker. If you can tolerate the hassle of tuning the antenna by slowly turning it and checking signal strength, you will get a better signal in the house. If you only have one bar at the roof, I would strongly recommend a (highly) directional antenna, a log dipole/Yagi style or parabolic. (Fiddly to align, but worth it.) Finally, don't expect great coverage inside, as the inside antennas are low power since they are close to people. Directional indoor antennas will project signal farther.
All the best,
Peter