Internet for an RV

I’d like to ask some of the networking experts here for any tips or thoughts. My wife and I received approval to work full time permanently remote, we both work in IT (outside of networking if it isn’t obvious by this thread). Due to this, we bought a 29’ Class C a few months ago that we completely gutted and have built into a mobile home and office to travel in. I’ve set us up to boondock rather than stay in RV parks, which means we will not have any hookups. 600ah if batteries, 400w of solar, onboard generator.

Questions:

-I’ve looked into a few reseller services for internet. Has anyone here had any experience using one? Examples being Nomad Internet. Basically a grandfathered SIM with unlimited and unthrottled data. We have 20g of data on each phone until it’s throttled via ATT, redundancy wise I’d like to get an unlimited sim through another network (Verizon, T-Mobile, etc) in case one network has better signal than the other.

-I feel a dedicated cellular router is a better option as I’d like both LTE and WiFi as WAN as options as well as the ability to tether our phones if needed for data. Currently considering either Mofi 4500 or Peplink Surf that I’ll hook to a roof mounted Mimo antenna. Looked into the Wingard setup as well as the WiFi Ranger line but without an internal router this would mean I’d have to climb to the roof to switch sims. The dedicated router should be a better option than just a standard hotspot like the Nighthawk, correct?

-I’ve heard that a properly setup antenna setup typically outperforms an amp or booster setup. True?

Open to any and all suggestions! I’ve done hours and hours of research on rvmobileinternet’s site and it’s a bit overwhelming.