The decision is mainly up to you,
Although this season I did try proving out my dinker male to a normal female. So far they all look like normals.
So, breeding your snake to a morph would have more benefits than breeding to just a normal. Even if you don't prove anything out, you still get morphs. But if you do prove something out, you'll most likely get combos!
If it were me, I'd breed to a morph. More benefits out of the clutch for sure.