I don't really buy into the 'more' is better school of thought on suspension. Personally, I would rather predictably lift a tire every so often, then deal with all the extra sway/roll that typically comes with large amounts of sloppy wheel travel. For me, it seems if the suspension can cycle a 9-12" shock that is a good all around compromise. I also like a bit more uptravel than downtravel if possible from the same ride height. This usually helps you increase spring rate slightly while still maintaining some preload at full droop.When I see a wheel off the ground it is a sure sign that the suspension has not done the job required of it.
Leaf springs need to be LONG to have better travel.
For that 10-12" of shock travel, I keep trending towards better shocks. The Fox 2.0 Resi shocks that Accutune did for my 80-series chassis based project are frankly amazing. On the F350, I keep coming back to how much shock DIAMETER I should do....not really how much travel. The other big question is if position sensitive valving would be worth it, basically getting into an internal or external bypass shock.