The entry for Howard county in the database suggests otherwise re the sheriff; in any case, the 246T won't do digital trunking. The 396 will, along with the Uniden BC296 and 796, and Radio Shack's/GRE PRO-96 or PRO-2096. And be prepared for a little sticker shock....
It might be tempting to buy a Uniden BC250 or 785; avoid these. In addition to needing a seperate card to enable digital trunking, Uniden will not support these 2 scanners once the various agencies begin shifting frequencies due to the upcoming rebanding effort.
I wouldn't give up on the AOR though; it's still a nice scanner for milair and conventional stuff.
73s Mike