There are people putting down decent times with supercrew F150s and 3.55 gears with bolt-on mods. Based on that I'm thinking a truck that weighs 500 pounds less and has 4.10 gears would be plenty quick with some of the common EcoBoost upgrades. Aside from taking the truck to the strip I'd be using it to haul my ATV, go hunting, and stuff like that so I'd probably keep the suspension as it is...I definitely wouldn't be lowering the truck any. If anything, I'd be more inclined to go up than down.
Whether or not I make the change all depends on the offer they come back with. I'd like to get rid of my SHO sooner rather than later given all of the problems it has had during the first 25k miles. I like the car a lot, and there's no doubt that it performs well, but I have little faith left in it from a reliability standpoint. Like I said before, the Tremor should be a pretty good fit for my needs in a second vehicle...decent performance, able to haul stuff, 4x4 for winter weather, etc.