I've been searching around for a hardtop myself and haven't had any luck yet, but when I do find one I plan on wrapping it in vinyl.
Just thought maybe you'd find that idea interesting before you go painting it. Its cheaper and allows you to use ideas such as various colour carbon-fibre effects etc. The 3M 1080 stuff is incredibly good quality and the range of options is very impressive.
Not for everybody, but I love the idea of a black carbon-fibre looking hardtop.