I'll give you my "take" on I-44 in SW MO and NE OK.
From Lebanon to Mt Vernon in SW MO, you'll want to monitor the Greene County PS system. It's mostly analog trunking and Springfield and many of the surrounding cities use it. Very good system to monitor... lots of interesting traffic to say the least. Most everything is in the "clear".
From Mt Vernon to the OK state line, you'll want to monitor the Joplin P-25 system. The Joplin police is mostly encrypted, but you'll hear everything else. For some strange reason Joplin feels the need to upgrade to the "latest and greatest" multi-million dollar communication system every 3 to 4 years. I've never figured out why. The county sheriff's office has used the same conventional system for 30 years and they do just fine.
From the OK state line to at least Tulsa, you'll want to monitor the OK statewide system. Load the control tower freqs along your route (Miami, Vinita, and Tulsa while in NE OK) and ALL of the talkgroups on the system. Many cities and government agencies use the statewide system and makes for some good monitoring. The OHP trying to maintain order on the Will Rogers Turnpike is good entertainment. You should start hearing Tulsa police about Claremore and that can get "wild".
All of the systems and freqs in the RR database are good and valid for this area.
I don't usually get past Tulsa... so hopefully someone else can help further south.
Happy travels!