Not sure if there is one available as of yet (haven't checked to be honest).
But I have done the main shell in PS 3D model form for doing your own paintjobs.
It's only a quick one, whilst we wait for the official release of the Reiza template assuming there isn't one already. If there is kindly disregard this one if wanted.
File contains two 3D model sizes for painting in PS 8192 and 4096.
Also included is a 2D 4096 sized template for those without 3D capability.
It's not brilliant, but will help out for now I hope.
GSC V12 3D model templates and 2D template. 2.0
Templates for V12 model painting designs.