My first rig was an 85 Truck and in an effort to be ready for family expansion I took an opportunity to get into an SAS 89 4Runner.  The 4Runner has all of the aftermarket parts that were on the truck plus Alcan springs, 2nd transfer case, cross over steering, larger tires, fuel injection and a winch, but the truck was still easier to wheel (I'm primarily thinking about Moab).  I think the combination of the extra weight, different weight distribution and shorter wheelbase make the 4Runner inferior all aftermarket parts being equal.  I wouldn't go back to the truck because the 4Runner provides utility that I'd never have with the truck, but the truck was amazing off road.

If I were you I'd jump on the opportunity to get the 4Runner as a DD, but wouldn't build it for off road unless you need the room or beat the truck up to the point you don't want to drive it anymore.  The truck will always be the better off road vehicle in my opinion.  You can take that truck places that would be very difficult with larger body of the 4Runner.