I'm not a kid anymore but I would suggest rohir peasant kid being armed for helm's deep battle.
I'm no sure if it appears in the books or not. To be honest I've read silmarillion and the hobbit lots of times but only once lotr. But it is one of my favourite scenes of the film, I guess it's really emotive.
You've only read LOTR once, but the Silmarillion lots of times? My friend, you may be in need of therapy... sorry, no, I'm being rude; it's just that I find all all those ill-tempered, squabbling Elves - and especially Feanor's brood - rather hard to abide, so I've only read it a couple of times. I'm sure their mothers must have loved them, but I find them less than endearing.
And for the record, no, no Rohirrim kids feature in LOTR.
"A worthy man, but his memory is like a lumber-room: thing wanted always buried."
He would be Sinda and not very tall but eager and iniative youth who is very young for an elf and isn't yet weary of Middle-earth. His passion is seafaring and shipbuilding in which he's being instructed by the very best, even by Círdan himself.
I would imagine him taking a break from his shipbuilding exercises (the physical part ie. nailing planks) wiping sweat from his brow and watching his handiwork while still having fine elvish hammer in other hand. His hair would be tied to knots typical to mariners. He would be cool addition to Mithril range I think because as far I know there aren't many fiqures from the havens of Lindon yet.
Shame I didn't notice until now that "main characters" are excluded – I obviously wasn't paying attention (way too busy) - so thanks to whoever edited the list for finding a way of keeping my suggestion in!
I really like the idea of the Arnor Hunter with Puppy, BUT, if it does make it I beg that the puppy is on the stand with the Hunter, perhaps on two legs and one paw on the Hunther's trousers? There is nothing I cannot abide more than trying to paint something buried in someone's arms. Think of the Red Book buried in Bilbo's arms as he sits on his chair. Or Merry/Pippin under the arms of the Orc? If Arnor/Puppy wins and I am not alone I hope you'll join your voices to mine.