Three great choices. Purely a matter of personal preference.
Amboyna is beautiful, but, to my eye, it is just too fancy for this particular knife. It seems better suited to a fancy gentlemen's knife.
To me, giraffe is great. However, I have tremendous respect for the wonderful Porch denizens who have expressed their personal feelings about this material. Since Mike has indicated he will probably use the second and third choices in a regular run, I cannot vote for giraffe. Why would we do that to our friends?
That leaves Ram's Horn. We have come so close to using this in the past. I hope this is the year.