Kelly;
The more I think about it,the more I think those 19.5's might be a good move,rather than the rear end change. I've noticed that a larger diameter tire usually produces a smoother ride,and I think you'd have more stable handling at highway speeds,probably less wear and tear on the drivetrain,and it'd look way cool,especially with the big rig fixin's on it. Just do your research and go with what looks right to you-these changes will probably be costly enough to make you want to get 'em right the first time.
Speed