For state, county, city emergency management stuff you usually want regional comms on 40 and 80m, like within a 500mi circle. 20m is usually used as a DX band to access other parts of the country and you need an antenna that will do both things well.
With that a horizontal wire antenna is the antenna of choice using NVIS on 40 and 80m but it will also work ok DX on those bands. An ideal height would be horizontal roughly 32-35ft off the ground. This is the best compromise for 40 and 80m NVIS, plus its the first half wavelength up for 20m giving you a low angle takeoff for DX. You can choose a center fed dipole that covers those bands, or an 80m offset center fed dipole (OCFD) or a resonant end fed halfwave with an 80m low end cut off. All of these antennas are around 133ft long.
You can attach any of these to the tower at the proper height but you will need at least one other attachment point close to the same height with the end fed being the easiest and the OCFD being the second easiest and a center fed usually needs three attachment points to be secure in high winds.
If you are considering a vertical, you will loose comms out of ground wave range, or you will have a dead zone from about 50mi to several hundred miles and that's not good for an EMCOM antenna. A Yagi or directional is not very practical for 80m but a good idea for 20m. If the organization has two HF radios you could use a horizontal wire for 40/80 to one radio then a vertical that covers 20m or a small Yagi that covers 20m to the other radio for simultaneous operation.
For OCFD or resonant EFHW antennas, the best I know of are made by MyAntennas. I have many of them and you take them out of the box, hang them up and operate, no tuner needed. The model EFW-7510-2K is a newer model end fed that is modified to cover the 75m voice band or roughly 3.8 to 4.0MHz plus all other bands to 10m and usually with no tuner. The OFC-8010E-3K is the offset center fed version but its tuned more in the 3.6MHz range of 80m but there is a simple mod to change that to 3.8-4.0MHz.