Based on what I've found online (bought 4 brand new 2016 20'' Tundra Wheels for $200; thought that was a steal - see them for $500+ online) they're:
Offset: 60
Width: 8"
Diameter: 20"
I'm about 99% sure you'll need spacers.. But that leaves 1% chance that the Terra's are more narrow than Trail's and they squeeze by the upper control arm.
Are you lifted? - Either way may need to trim / heat mold some of the wheel well liner over the pinch weld.
The set up sounds awesome - can't wait to see pics.