Having purchased a 3500 tradesman with the RA1 radio, the cheap cluster, no overhead console etc. I can tell you, yes you can change the cluster, the radio, add the overhead console etc. But to be honest I wish I had just gotten a higher trim with these options to start with. Some of the mods were PNP some required extensive research, fabrication of harness that were not present in the truck and in many cases not avail for purchase, not to mention the cost. The thing I am sure about is I would have been better off just getting these items in the truck to start with and I the end it is still a tradesman.
Here are the things I have been able to do;
Upgrade to 8.4AN nav radio
Add overhead console with home link
Upgrade sun visors to lighted vanity ones
Add OEM backup camera
Add additional upper glovebox
Upgrade third brake light to LED cargo camera
Upgrade gauge cluster to 7" premium
Add underhood light (tradesman do no come with them)
Add footwell lights (tradesman do no come with them)
Upgrade to leather steering wheel, cannot hook up heating element though
Add steering wheel audio control buttons
Here are some things I want to do but are either too much money or just cant be done;
Add OEM heated and cooled power seats
Get the heated wheel to work
Upgrade tow mirrors to OEM power fold
Register my 8.4 with uconnect
Add the OEM aux switch panel
Add OEM fog lights
Add OEM front and rear park sense system
I'm sure ther are a few other things as well but these are the biggies