Is it better to use GUI or something else for simple rotating graphics on mobile?

I have a physical game board that I want to digitize. I am hoping to utilize Unity for this partially to get experience in Unity and I also like the ability to push out to multiple platforms.

The game board will be completely static except for 6 wheels that will rotate in place from user input. Each of these wheels has a section cut out to show text underneath.

My question is whether it would be better to make these all GUI object or make them into something else to be able to accomplish the above.

The OnGUI function for mobile devices is a bit heavy. You will also find it a tremendously amount easier to treat the game mechanics as GameObjects. If the objects are flat then you could add them to planes (sprites), but they still live in 3d space. A good start for draw call optimization is a sprite manager - although with few components you might not even need one.

Early in your programming you’ll cross transforms and most likely rotations (where transform.Rotate() might even be enough to suit your needs). Text could be done with a TextMesh-component. Further on you probably have to handle some shaders to both optimize and make certain objects render in a specific way, often rendering order and the way transparency is handled on mobile devices.