I have used the Austin Spectra antenna for several years and find it quite good. It's tunable for the 30-50Mhz band and includes a cutting chart. Mine is cut for 42Mhz CHP. It can transmit on 2 meters and 70Cm. I use it as a backup ham antenna. I have used many mobile antennas since 1969 and this is one of the best. Not cheap, but you get what you pay for.
In my truck for the in-dash mounted Pro-2096 I have a RS mag mount scanner ant. that I ended up having to mount to the back of the cab in horizontal orientation in order to control the simulcast distortion. For my handhelds (Pro-18 or Psr800) that get mounted in holders either suction cupped to the windshield or vent mounted I just use the stock rubber duck and I don't seem to miss that much if anything with both radios working the same scanlists.
Considering your location (from your ham call and checking the associated counties in the RR Database) and the very generic description (normal police and fire frequencies and some P25 systems) of what you want to listen to, I would recommend a good VHF/UHF dual-band ham antenna. It should provide great coverage on the VHF-Hi and UHF frequencies in use by the agencies in your area. Since you have no significant PD or FD use of the 800 MHz frequencies or the VHF-Low band frequencies, you can eliminate those from your antenna choices and be able to get one with a reasonable size and good gain.