A dakota frame is a better fit than the S-10 frame. Its the proper width, has the proper track width, and doesnt have the steering box to radiator interference problem. Knowing what I know now, I would not do an S-10 frame swap. Live and learn.
A full size will make the tires stick out past the fenders about 2.5" per side. You could swap out a big-bolt front clip and then get the 2" wider aftermarket fenders. This would run you about $200 for the clip and about $600 for the rear fenders.
What is wrong with your existing chassis that you want to change?