Sorry - I tend to view things from the Fire side of the desk - that is what I do for a living.
As far as "interoperability" with surrounding Counties/Agencies, we are all part of the Los Angeles County Regional Tactical Communications System, which has VHF/UHF/800MHz components. It works much better for the Law side than ours, but it does work, allowing different Agencies, with different frequency bands, to work together through a common radio system. We had a few fires this last season where it got used. I know Simi PD (prior to going UHF) and VCSD use it for pursuits that go East of the border.
The system wil remain analog, and I am pretty sure that will be on both sides of the desk, Law and Fire. For the VCFD, it will be simulcast on the dispatch channel, and repeated/simulcast on all the 7 or 8 command channels (for different geographical areas around the County). Last I heard, for the VCSD, it will be repeated simulcast for the 3 primary dispatch areas, East County, West County, and North County (currently there, but not used).
I don't have the final channel load, as it has changed a little since the original RFP went out. I will up date the board and submit it for the database once I get the final version. In any case, nothing will change for at least a year.