Enamel gives a much better shine and will more than likely give you no problems. 3-4 light coats should do it nicely but test it on an inconspicuous area first like in the well of the deck where it would normally be covered by the carby and the fuel tank.
As for the wheels/caps its probably easier and cheaper to get a decent set of 2nd hand ones. Plastic paints and primers are quite pricey and will ultimately scratch and flake.
I'll send you a PM and we'll try and organise a set of wheels for you.
