Palmetto P25 is a digital APCO 25 system, and unfortunately for you, only the higher-end digital (ie, expensive) scanners are able to monitor this type of system. There are several models available now from both Uniden and GRE/RadioShack. They are all "older" models that have been available for several years. GRE is no longer in business and radios made by GRE are more difficult to find new and are no longer supported. Uniden and Whistler (the company that is apparently filling the gap left by GRE) have both announced new scanner models that will be available next year. These newer models might have better performance on these P25 simulcast systems - that remains to be seen.
You can search the RadioShack web site for the PRO-106 (handheld) or PRO-197 (base/mobile) scanners (same radios as the GRE PSR-500 and PSR-600). They aren't available online (since they're no longer manufactured, stock has been depleted), but do a search for stock in local stores. Many folks have had success with these models. You might find these on sale for around $400 new this time of year. Programming software and programming cables cost extra and most will tell you they are necessary
Uniden has the HP-1 as well as the BCD396XT and BCD996XT. THese are available online from many different retailers (probably none locally unless you're in a location near a ham radio store line HRO). Costs for these are probably higher than RadioShack, but they come with free programming software and programming cables, which cost extra from RadioShack.
You can also look for the GRE PSR-800, but the costs of these is rediculously high in my opinion.
You can also consider older digital scanners on the used market (eBay, RadioReference Classifieds, Craigslist). But keep in mind that older digital scanners like the PRO-96/PRO-2096 and the Uniden BCD396T and BC796D will probably not work as well on this particular system type. In the three areas of the state which the Palmetto P25 system is currently operating, all are simulcast systems. That means they transmit the same information on the same frequencies simultaneously from multiple tower sites in order to cover a large area. This type of system causes problems for many consumer-grade scanners and can cause frustration for the listener. One's location in relation to those various tower sites greatly affects how well the scanner will receive.
Out of curiosity, what area of the state does your father live?
Hope this helps.
One more note - regarding "simplest," very few people would agree that any of these scanner models listed above qualify as "simple." That's just a function of modern technology in this hobby. Be prepared to spend some time learning how these radio systems operate and how the scanners can be programmed best to monitor them. It's a rather steep learning curve.
