I'm with Jesse on the Target Clone deal. Even though both of the BARC clones on Saelucami had the same helmet, and none of the Target Clones were on screen at all, I would assume they were the "unseen grunts" of the Saleucami task force. As such, I'm more than happy to have one in my collection.
If it's a Clone Commander/Grunt/whatever variant that looks like it could have been in the film, I have no problem with it. Even though I'll probably end up getting one of the Stealth Clones and the black pilot (if I ever see one), they're a little less interesting to me than something like the Shocktrooper, or Bacara's grunts from Mygeeto. A Clone Commander with green markings is fine with me from an EU perspective, but when you start getting stuff like the POTF2 Crowd Control Stormtrooper, that's when I begin to pass on them.
In reference to the "weirdo" helmet and 501st Commander photo posted by Dressel, that photo comes from the "Art of ROTS" book, and there is a second photo of Commander Faie to the left of the aforementioned photo that has him wearing a kind of "mini-cloak." Also of note is that the red Clone Commander that we've already gotten as an action figure is identified as an "ARC Trooper (Color Variation)" in the photo to the right of the Neyo/501st/Faie photo.
And just for completion's sake, an excerpt from the text:
Lucas's desire for individualized clone trooper armor as expressed during the very first art department meeting back in April 2002, has a continuing effect throughout post-production as Jaeger creates several outfit variations. Though they are essentially dictated by climate, some are takeoffs on the armor seen in the Clone Wars cartoons, while others are throwbacks (or throwforwards) to the Episode IV desert stormtroopers.
Also of note (although not relevant to this discussion) is that pictured on this same page are four photos of differing "deco damage" on the MagnaDroid bodyguards, one of which is the white version that everyone shook their heads at from Hasbro's "Final 12" ROTS figures.
And just to plug it (since I really like it myself), the Art of ROTS book is a great resource and a really good insight (like all the art books for SW) into where a lot of the characters came from. Well worth picking up.