Hmmm, of my two main characters, if this is a fantasy thingie (seeing as one has passed away)....

Terminotaur: Andreas Katsulas somewhat in the role of G'Kar (maybe an octave lower)

Terminotter: A toss up here as I'm still trying to decide if I want him more fun or serious, but both voices are by James Arnold Taylor. Either a bit like his Obi Wan Kenobi from Clone Wars, or his Ratchet from the Ratchet & Clank games.