Get "Smooth N' Easy" Epoxy from HobbyPoxy. It is relatively thin, so it pours into molds better than most epoxies (although Pic's Coating Poxy is thinner when poured, it cures very stiff). The HobbyPoxy Smooth 'N Easy is quite flexible when cured, the perfect stuff for casting corrugated body wraps. I used it for my NARAM-33 Peanut Little Joe II (bending around a 1.5" dia tube!), and Jay Marsh has used it for his 1/66 scale Saturn IB corrugations.
Since you plan to cast using the Centuri wraps as masters, this isn't as important, but for corrugations that are very small between spaces it can help to add a bit of dye to the epoxy to help see air bubbles. Not much dye, just enough to tint it to be translucent, which helps show up air voids as lighter-colored "bubbles" amid the darker properly filled-in recesses.