Well here's the break down:
Buncombe EOC & the rest of the local small towns will be just fine with a plain analog scanner.
Asheville City is currently on a Moto Type II trunked system, with all channels being analog, BUT, at some point in the future APD will be switching to digital and AFD will possibly follow.
Most VIPER traffic in the Asheville area is SHP, which will be exclusivly digital in the very near future. Bear in mind that SHP is still simulcasting the dispatch side on low band if that's enough for you (I never could get the mobiles before VIPER anyways). Other traffic includes digital VMN channels for patient reports to the hospital and local mutual aid channels; I'm sure MAMA will be onboard before too long as well.
I'm not too terribly sure which route the county will take with the med reports, ie stick to MED 5 for calls to Mission or jump on board with the VIPER Med Net.
That being said, I would recommend a digital scanner, but you could go a short time without it and not miss out on much. I have a BCD396XT and personally I love it. I would gladly help you get it setup and working for the Asheville area if you do go that right. I'm sure the previously mentioned PRO-96 would work just as well, but I'm not as experienced with that scanner. The same holds true for the GRE PSR500 / PRO-106.
Hope this helps, if not, keep asking questions and we'll get you on the right track.
Regards,