Toyota 79 Series
The 79 is an awesome touring vehicle, but I don't have to tell you that as you know already. This truck will take any roof tent - but the thing to watch is weight over the rear. Newer installs have been concentrated on running the tent over cab - rather than over the canopy, centring the weight and maintaining max traction over the front wheels.
Roof top tent camping has its drawbacks as well as its advantages - the big drawbacks are negotiating the ladder straight out of the tent. If you can mount the tent further forward, you get the opportunity to run a platform and if possible some empty tray at the rear - negating the need for full-height ladders.
Worth thinking about!