So what about antennas? Well the "right" answer is there is only the FCC approved 2.1dBi 4" articulated dipole available from Digi for $5. That's the short little one in the front.
I've tested this one consistently to over 500' across relatively even ground. And it even worked once to more than 1500' when I was on a small hill. That's with the 2.1dBi on both ends.
The middle antenna is a 5.5dBi Omni that I obtained domestically. Theoretically it has around twice the gain as the 2.1dBi. The same company sells a 9dBi Omni antenna that would be a marginal improvement again. I particularly like the 5.5dBi Omni because when it folds over it still fits inside the field box. The 9dBi would be too long.
The monster at the back is a 2.4gHz Yagi I ordered from Hong Kong. What I liked about it was that it already has a RP-SMA connector on the cable so it is plug-and-play with my system. This one is advertised as 16dBi. It is highly directional of course.
I have found in my experiments that getting the antenna up off the ground is much more important than the antenna itself. And this makes sense. A 4" full-wave dipole 6" off the ground will be greatly challenged compared to a similar antenna 5' off the ground.
Out to 100' the small antenna works fine. Out to 500' the small antenna works but it needs to be elevated. In these situations a higher gain antenna at the field box end improves reliability.
The Yagi is the wild card. Line of sight it will work to a mile and more. It's easy to put the Yagi about 5' up on a tripod next to the field box and point it at the LCO. At the LCO we just need the 2.1dBi or one of the longer dipoles. If the antennas can see each other they will work. So this is the solution out to 2000' and beyond.
So what about antennas? It depends (my favorite answer).