Drool
while you listen
Unfortunately, I do not have the patience to learn how to make winamp skins. Instead, I've compiled a list of sites that do have skins of Riku, so please venture over there to get them.
Divide by Zero - Contains two skins of him: one from the KH opening, and one from Deep Dive.
Happy Phantom - Contains one skin of him: KH concept art where he leans against stone wings.
Speculate - Contains one skin of him: KH concept art where he's just standing.
Space Cat Samba - Contains two skins of him: KHII cover art & KH:CoM concept art.