Try checking out Annabella's choli pattern - it's free online - in all sizes, and easy to construct.
Turbans, Tassels and Tattoos! - American Tribal Style Belly Dance in Australia
It does require a stretch fabric for good fit (like panne velour) but we've used this one LOTS and I love the look and feel. You could keep to natural tones to match the rest of your costume pieces.