Beings your down under I'm not going to comment on price, you can pick what fits your budget.
If your color choice is a metallic you might want to use a base/ clear because it's easier to get good results,but cost is probably higher.
If your choice is a solid color I would suggest single stage acrylic enamel.
Straight enamel I would only use on farm machinery and then I don't like it because of it's fast fade out.
There really isn't much downside to B/C except the price and you have to paint it twice. Once with color and then the clear.
Single stage enamel, paint once and your done, but unless your a great painter metallics are hard to deal with and get a great end result. Their cost is probably less.
As with all paints you don't want to breath them, but modern urethanes are real toxic making that a downside.
I hope this helps.
Dan
