I think both would work.
Would you prefer one that pops more .. then the dark chocolate.
If you'd like a quilt that's more subtle and subdued, then the milk chocolate.
mmmmmmmmmm chocolate!
Not sure what your whole quilt plan is ... but with all those fabrics, maybe you could do some of your blocks with dark chocolate ... and some with millk? Or use one for background and the other for sashing?