Speaking of character height, if they ever made Voss playable, they'd have some really tall ladies. At least I'd hope they kept their height consistent with the NPCs.
There's a reason why we probably won't see playable Wookies, and that's simply because every single piece of armour in the game would need an alternate texture to fit on their frames (given that legacy/cartel market allows the unlocking of every species for every class). This would go for the Voss or any other species that wouldn't fit into the four body types already in the game.
As it is, they took a short cut with Bowdaar. No armour shows on him, and the only way to change his appearance is through customisations (much like Khem Val and Broonmark). They'd never do that for PCs, though - it would be too much work.