I’ve had to deal with gates at a couple locations.
1. Emergency access: you can install a Yelp sensing capability. Emergency vehicles hit the yelp function on the siren to open it. Check with the sheriff or police for their requirements. Will be part of permitting for the county.
2. Access programming. Assuming you aren’t going to have internet or cell modem on the gate, you will have to keep the software access database on a notebook computer and go to the gate to update.
3. If you have phone line or internet on the gate, you can program, allow access and open the gate remotely. Without that, anyone coming through will need an access code. For security, you will need to load a bunch of one time codes or risk the codes getting spread around with the loss of security.
4. Power. Are you going to run grid power or solar/battery? You should have backup power capability for emergency access if grid power is down.
5. Gate type. Rolling or swing. Each has a different hanging requirement. Exit sensor. Buried mag loop, optical, keypad each has pros and cons along with levels of security.
Get several quotes from good companies if possible. Have them option out the configurations that will work for your site.
See if the other land owners will agree to deed modification to incorporate an association for the purchase of roads, gates and insurance if needed. You won’t be there forever and this is a large investment. Maintenance can be significant.
Good luck.