Cobra Commander! What about a Cobra Commander that comes with a Starscream shaped and colored jet? The actual jet would have to be bigger than the original Decepticon toy so to accompany the 3 1/2 Cobra Commander inside the cockpit so Stars would have no problem transforming as well. You could place either COBRA or Decepticon symbols on the wings. And the voice chip? The wicked Latta laugh!
I would just settle for a GI Joe Skystriker painted in SS colors. Not the correct jet, but it would be cool!! WHY has no one kitbashed this?
Or rerelease Masterpiece Starscream with a small Cobra Commander figure that is scaled to Starscream.
This would seem most efficient. Maybe leave out the tampo symbols on his wings and give you stickers for the option of Decepticon or Cobra symbols. Something I do with my alternators is to make cardboard cutouts to "drive" them. Among these cardboard cutouts is a cardboard Cobra Commander and a cardboard all-blue Dr. Tobias Funke. Believe it or not, it actually looks pretty cool. I think this thread just convinced me to paint Dr. Arkeville blue with a silver face...or to make a tiny Cobra Commander out of cardboard...