What is the best cell phone signal booster on the market?

My boss has a 34 acre property in a rural area. He wants to be able to make calls without them consistently dropping and send/receive texts in a reasonably quick manner.
I have started researching cell phone signal boosters. I don’t need the kind that attaches to the phone. I am looking for one that has an antenna, amplifier, etc. I also need one that can boost the signal significantly over the 1.5 million square foot property.
I have seen some of the stuff that Wi-Ex offers, and it seems pretty high quality. I’m wondering if there are other options out there as well.