Why don't you look into buying yourself a good slightly used Yaesu VX-170 or a FT-1802M ham radio that has the sensitivity needed to pick up those RR frequencies. The VX model is a handheld while the FT is a mobile unit that can also be used as a base station. Both are amateur radios and to listen only, you don't need a FCC license. Railcom.net sells a nice already assembled & cut magnetic mount antenna with cable including the BNC connector. The VX will require an adapter to use the antenna as will the mobile. hat you want for the VX is a Diamond SMAP-BNCJ adapter while for the FT, you'll need a PL-259 to BNC male adapter. The FT requires 13.8 VDC power from your vehicle which is easy to connect while the VX uses battery power and/or an mobile power adapter.

There is radio programming software, but unless you're a FCC licensed radio operator, it's by far cheaper to just program into the radio those desired RR frequencies. Not saying that in order to buy the software you need a FCC license rather the software is to program into the radio a great many frequencies & features unlike the few involved for just casual RR listening pleasures!