It looks like the Cochise County P25 Phase II system has 4 standalone trunked repeaters, as well as a simulcast system.
A simulcast system will have 2 or more sites all transmitting on the same frequencies at the same time. This is called Linear Simulcast Modulation (LSM), and can lead to issues for most scanners, even those otherwise capable of P25 Phase I and P25 Phase II reception, due to multi-path interference preventing them from being able to properly decode the digital signal. If that is the case, it is possible that your only real choice may be the new Uniden SDS-100 which is designed specifically for improved LSM reception, or if you want to wait, maybe the two new Whistler's later this year, which are also supposed to be designed specifically for improved LSM reception.
I would suggest going to the Uniden forum and reading up on all of the SDS-100 threads. It is not a low cost scanner, and having just been released, there are some issues being worked out still. Others have not had any issues, or at least not any major ones. You should read up on all of it before deciding to buy one. (I want one myself, but may be forced due to finances to wait instead of gifting myself for my birthday next month.)
John
Peoria