Yeah, I like those planetary gear motors. When I used the Pololu motors with the spur gears we had to devise a method to take the load off of the motor shaft. These planetary gear motors seem like they wouldn't mind a direct load on their shaft though.
I have some of both sizes of the Pololu wheels. I've been using the 7.9" wheels, but I have both. I'll probably experiment with the different options.
I wonder if Servo City has any good options too? It can be nice to source everything from one supplier if possible without any compromises.
I probably won't be buying new motors until April, but I have started experimenting with using Ubuntu MATE 20.04 on the Pi, as well as using a non-xbox360 joystick and I'm just starting to tinker with ROS + Roboclaw.
I probably will build a new entire chasis for my next "arlobot" type robot, using 3D printed parts. I just haven't had time to design it yet.