You dont really need a clear coat, in fact if you want it flat black, you're probably better off without one any way...

But yeah, rattle can is the way to go if you just want flat black, and as far as taking the tires off, It is easier, but you'll spend close to a hundred bucks getting them taken off, put back on, and then balanced.... Guess it depends on how expensive you want to make this...also, you can get a body shop to do this kinda thing for probably not a lot of money, cause they dont need to match paint, or really tape anything off, all they need to do is spray it with any flat back they have in the shop....One local to me does it for 30 bucks a wheel...note that this is much more expensive than a rattle can....hehehe

later,
Aj