Depends.
If you only want to listen to Lancaster county and city of Lincoln then you will need a scanner that will work on an EDACS trunking system. Most modern scanners will.
If you want to listen to NSP you will need a P25 digital scanner. Newer digital scanner will do.
Go to the wiki look at Radio Shack, GRE and Uniden models. There you will find a list of their scanner models and what type of system they work on.