alloywheel,
Yes it's possible to polish the 'hooding' on your wheel manually. After the machining work is done, you will have to remove the polyester paint/powder before you start to polish.
How rough the surface is would determine what grit of sandpaper you would start with.
Check this thread out and then ask your questions.
MOTORCYCLE POLISHING 101 CLASS IS IN SESSION!
What kind of polish are you looking for? The time it would take would be based on your experience level or how long it takes to become proficient!
John