As someone who works in the Edison NJ area, I can assure you that the absolute best scanner for monitoring these towns above is the Uniden SDS100 (handheld) and the SDS200 (base/mobile) scanner. No other scanner will work correctly, despite promises to do so. One of the issues is simulcast distortion, which is described ad nauseum on this site. Also, the SDS series of scanners has a lot of programming flexibility to it, and that is just one of the features that I like. I use mine for disaster ops as well, along with everyday monitoring of various situations. While a growing number of police departments nationwide (including NJ) have moved over to encrypting/scrambling their communications, you can figure out a lot of what is going on by monitoring Fire, EMS, and even DPW (Dept. of Public Works) channels/talkgroups. In fact, sometimes you'll know more of what's going on by monitoring these channels/frequencies than just police alone. Most OEM (Office of Emergency Management) channels are also in the clear as well. I'm not sure about the Federal level such as FEMA, but users have reported mixed encryption in use, in the past. Hope this helps you out, and if you need further clarification, just ask and we'll be here to guide you correctly so that the money spent is well worth it.
