I think you'll find you're going to get caught between a rock and a hard place.
You need to consider the number of simultaneous 'high priority' calls that can occur in such a huge area as might be defined as "the Metro area". You're also going to be somewhat hamstrung by the inability to manually set a delay time on the HP-1. It's a cute unit, but just shy of perfection.
Unless you're prepared to invest in more hardware than just the HP-1 and the PRO197, it's not going to be possible to achieve what you hope to achieve.
The LE action in the Metro area by itself can keep two scanners operating pretty much full time, even if you avoid all of the data/clearance channels.
Trying to add FD and EMS action to that ... more hardware and ears that can multitask exceptionally well are your only hope of 'hearing it all', and even then, you have to be prepared to miss some stuff.
In your shoes, I'd consider paring back my coverage area to something a bit less ambitious, redefining "around town" as a somewhat smaller patch of turf.
