Here's 31x10.50R15 tires on my stock height 77. It had the HD springs.

This one is Front: 32x11.50R15 REAR 33x12.50R15. The 33's rub a lot on the front, but the 32's never had a problem.
This truck had the Light Duty Springs.

As far as control, Unless you're gonna be burning up the winding roads, I'd just pick the size tire you like the looks of and call it a day. I don't have any problems with my 275/70R18 Tires and I drive the crap out of my truck. But I have the big swaybar and stiff springs.
Best thing for better control is to add a swaybar if it doesnt have one, or get a bigger swaybar if it does have one, or add a rear swaybar.