I can see why people would want the Kup remold to be Orion Pax, but I just don't see it. Truth is that I have ABSOLUTELY NO IDEA who it could be. There are a few good suggestions out there, but nothing feels quite right to me.
As for Scourge, there is equal evidence that his remold could be either Ratbat or Leozak;
[Ratbat] Aside from the head looking pretty close to the comics, the strongest case for Ratbat is the fact that we are getting Frenzy/Rumble soon as well. Add in a new Lazerbeak and we have most of Soundwave's entourage on our shelves.
[Leozak] One word; Blackshadow! If we are getting an obscure (to American audiences) character, albeit as a remold, then it makes a fair bit of sense that we could see other related Japanese-exclusive characters to support him.
My personal vote goes to Ratbat, mainly because I want to have more updated Cassette-Bots to display alongside the most evil tape deck ever! Either way, though, I think I'll be happy!