This upscale of an Estes Orbital Interceptor is built with LOC 2.6" tubing and an Aerotech nose cone.  Fins are 3/16" ply, with the exception of the tail plane (which is 1/8" ply).  The tail plane is gussetted with triangular balsa stock and tabbed onto the rudder.  Motor mount is 29mm, and can accept a 6-grain case.  This model can handle full-H motors reasonably, but a small I would be the limit.  Vinyl decals from Stickershock23.