I was surfing the internet this afternoon and came across this great website for all your luau party supplies - Hawaiian Luau Party Supplies. This is a most comprehensive collection of items that will make your luau a success. Among my favorite items are the grass skirts, tikis and ukuleles. The website has a nice sidebar with information about luaus, such as party decoration ideas, luau serving suggestions and also historical information about tikis, ukuleles, and hula.
Online shopping makes everything so accessible these days - it's awesome. You don't need to live in Hawaii to have a truly memorable luau - just a credit card and a bit of creativity!