How tall are the Iksar going to be?

[Videri]

I can't say one way or the other whether Iksar were as tall as Barbarians when they were introduced to Norrath, but Iksar do have a slightly-larger-than-Medium size. They are not as tall as Barbarians, but they are definitely taller than Humans and elves.

Throwing Boulders are indeed a good example, usable by large races and Iksar. Gatorsmash Maul is another, usable by large races and Iksar.

Mroons Toy and Midnight Mallets are equippable by large races, Iksar, and Dwarves.

Those are not evil items (no Dark Elves) or lizardy items (they're usable by softskins, after all); they are large items usable by the largest and strongest races of Norrath.