Project Which Mill is best suited for small aluminum bowl?

I am making small aluminum bowls out of sliced aluminum rods. The Sketchup file is attached. I am considering the OpenBuilds mini mill which could cut the dimensions I am looking for, or modifying the C-Beam mill so that it has a larger z-axis travel.
The inner bowl needs to be as smooth as possible.

1. Can the mini mill do it?
2. Which bits would I need to get the smoothest inner surface?

 

Hi Grantman,
Is it possible to get a smooth finish using the mini mill? The mill is more useful for upcoming projects even if a lathe is better suited for this one.