Cant say that i know much about what you are doing, but i can make some educated guesses.
When you get them media blasted, you are going to end up with very very small pitted texture on the wheels. The texture will be uniform if done correctly, but I'm afraid the look of your wheels would be that of a very dull silver.
I guess the big question is what type of look are you after? I'm just thinking that when you get them blasted you would have to at least wet sand them to get a smooth looking finish before clearing them.
If you are just looking for a silver finish, it may be easier to strip the clear off the wheels, wet sand any rough areas with 600-800 grit paper, spray a coat of silver wheel paint, then clear.
If you are looking for a polished finish, media blast the wheels and then wet sand them with 800 to 1500 grit paper. then take a buffer with some aluminum polish and shine them up. then clear coat them.
Like I said I dont have much experience with this, but I do have a sand blasting cabinet and have seen what metal looks like after a quick blasting.
Hope this helps you a little.