Getting that thing to not drive like a truck just isn't gonna happen. Solid front axle pretty much throws that out the window. If you end up replacing ball joints, I'd use offset uppers to give it some extra positive caster. IMO, it makes them drive a good bit better, although it does increase steering effort a bit.
If you want tires that'll handle the load of towing a bit better, and be a little more stable with the weight, I'd move up to the factory option size of 245/70R16. The price difference should be minimal between the 2 sizes. 235/70R16 or 255/65R16 should fit fine as well.