I have a PRO 106 as well as a 436. First, since Whistler took over the GRE company...they made the 106 for Radio Shack, they no longer carry them in their catalog. Therefore, if you want a 106, you will need to find a Radio Shack that still has one in stock, unless you are planning to buy a used one...which I would suggest never do.
The PRO 106 almost makes it certain you will need to buy the BUTEL software for programming. The software on the 106 can be very difficult to program manually. You will need to buy a cable from the shack.
Also realize that the 106 is great, but will not pick up the new TDMA phase I and II radio systems, which many states and county's are beginning to use. It is in place here in northern Illinois, and only the 436/536 will decode it.
Just some thoughts. And I don't even live in Kansas.
Yes, just get the 436 or 536. Don't buy something that's already been out 4 plus years