I too like the pink #7 (original). I like it a lot. The koko is smaller than the others and thus seems appropriate on the smallest denom. I think the pink works for the nickle chip too.
I like the blue #4 chip. The foot gear is unique on the Koko and I think it works well on the blue chip. He's also a shorter koko than others and that makes sense to me for the two lowest denom chips.
I like the brown #2 chip and agree with RanMan about this Koko design being a winner because of the traditional hunch-back design, but I prefer it on the brown rather than the blue.
I like the sand #6 chip (original). The head dress is very unique as is the shape of his instrument and his clothing with the stitching at the base.
This would give us 5 right-facing Kokos and 4 left-facing Kokos.
Do we need/want a NCV chip too? Perhaps a left-facing one?
If so, my vote would be for the high-stepping #1/5 chip that's on the original blue, but reversed so that he's facing left. Perhaps on a taupe colored chip with a very colorful and contrasting border.
-jamby