If you go with a Uniden scanner, you will need a BCD396T if want handheld, or a BCD996T if you want a base model. The older models that will also work are handheld BC296D and BC796D base. You can download ARC396 and ARC996 from Butel at www.butel.nl for the newer models, or ARC250 for the older models. It is something like $30.
If you go with a Radioshack scanner, the Pro96 handheld and the Pro2096 base are the only ones currently available. They are programmed best with Win96 found at www.starrsoft.com. Same thing goes with $30 to purchase.