For the 2002 storyline, there's really not much to be added. It has all the same characters, except for a few new ones. These are the ones I'd need to add.
Cahdok-T. J. Storm
The same goes for 2003. Of course, I'd have Tom Holland playing Takanuva as well as Takua, but there's really no speaking characters to be added. I mean, I seem to recollect that the Bohrok-Kal could talk, but I'm going with the idea that the 2003-storyline movie would just be a big-budget version of Mask of Light.*
*Also, I'm not too fond of the Bohrok-Kal in general...
To prevent spamming you with posts, here's my cast listings for the Metru Nui story arcs.
Makuta Teridax-Andy Serkis
Turaga Dume-Mark Rylance
Morbuzakh King Root-IDK
The Shadowed One-Ralph Fiennes