I think (with a strong emphasis on "think," because there are others on this forum much more experienced than me on such matters) that the best two ways to get a Randall with great Stag are 1) to purchase it after it has been made, and after seeing photos of the completed knife; and 2) supplying the Stag as CW handle material. For #2, many of the authorized RMK dealers, with Gary Clinton being but one example, have their own supply of Stag, and can supply it to the shop as part of the knife order.
Many times, though, the shop-supplied Stag is outstanding. My first #5-6" has shop-supplied Stag:

My youngest son's #5-6", which was his high school graduation gift from me, also has shop-supplied Stag:
