Well, no one else answered...it depends on what you want to listen to and your budget. All around, I'd vote for the SDS200 (for mobile/base) - it will handle most of OKC, OWKIN, OMACS, and the business stuff, as well as air and federal. If you want a subset of that, there may be other options that could be cheaper or smaller! a Unication receiver is a handy portable to use in the area - works well for OKC and other P25 trunked systems around. I'm sure others have opinions, but that's what I've settled on for mobile/portable. SDRs are another option for base work - but tough to take mobile/portable - but the cheapest by far!