As far as I know, there are only a few upgrade kits released for G1.
Crazydevy made ones for Superion, Devestator, Predaking, and maybe the seacons? There was a G1 Jetfire/Skyfire head coming out but I think the project may have died.
What, specifically, did you want to upgrade on the characters you listed?
I know that there are a few more add-ons via the 3D printing service Shapeways (shapeways.com).
On the lookout for MISB Headmaster Highbrow, Takara or Hasbro. I'm sure I could make you a sweet deal!