4 cans will do a set of 17" wheels, they will try sell you "pre dip" no need for it really and no primer is needed
a good wash is all you need then let them dry and they have to be bone dry!!!! water sits under it and bubbles like rust
you could get some panel wipe on them
Save masking up get some notecards/playing cards / business cards , then place them around the rim
You need a very light mist coat first! about 40-50% coverage
then build up to a second and third coat
aim for your third coat to just about cover the existing colour, Then you can go full on !
you can add pearl or glossifier over the top