No maps handy, but for easy and scenic, starting in Silverton, I'd suggest:
Silverton to Animas Forks - easy 2wd
Animas Forks to Lake City - Engineer Pass, easy 4wd
Lake City back to Animas Forks - Cinnamon Pass, easy 4wd
Animas Forks to Hiway 550 south of Ouray - Hurricane and Corkscrew passes, easy 4wd
Hiway 550 to Telluride - Ophir Pass, easy 4wd
Telluride to Ouray - Either Imogene Pass (incredibly scenic but perhaps a bit challenging and/or intimidating). Moderate 4wd.
Alternately,
Telluride to Ouray - Last Dollar Road back to Ridgeway and Ouray -- easy 2wd and quite pretty.
None of these roads will seriously challenge a stock 4runner.
I would budget 2 days minimum for doing all of that. Lots of places to stop and take pictures.