[Kanibal]

you could always get the stuff in the can. there are a few places that sell it like duplicolor. thats about the cheapest way to go without sacrificing too much quality.
the more professional way to co about it would be to powdercoating its sprayed on then baked. this is much nicer and stronger than the spray can and it can be any color you want. it is however more costly and has to be left too proffesionals. but you get what you pay for.
while you dont have to remove the tire for the spray can it is strongly recomended for a nicer result. as far as tools go it depends on how nice you want your results to be. to do it right you will require a few cleaners some sandpaper or steel wool and maybe some masking tape depending on your wheels.
just remember when painting anything the first rule is the better you prep the better your paint will be.
I personally whould go with a powdercoat just because its way nicer than a spray can and its stronger its just not as easy on the wallet.
I personally have not done any of this so I cant give you a price quote.
as far as time it depends on many things such as your skill level, humidity, drying time between coats, prep time, number of coats needed, and so on and so forth.
and for powdercoating it depends on the shop and how busy they are.