We've talked about all of this before in your several previous threads about the same topic.
You have a lifted truck with big tires. Adding cams can increase power, but it's going to do it higher in the rev range, which means it will make it feel slower off the line (where rpms are low), and faster on the top end. That's the opposite of what you want in a truck with big tires. It's also a pretty in depth job best handled by experienced mechanics/wrenchers that requires more time and special tools. That's not cheap.
If you're sticking with the lift and big tires, you want more torque, not necessarily more hp. The only way you're really going to get significant torque gains from a 2.3L 4 cylinder is a turbo setup, and that's going to be completely custom. You can go back and review your previous threads about turbo duratecs to refresh what all would be required to make that happen.
If you want cheap-ish gains from small, bolt on mods you're down to removing the clutch fan, getting an underdrive pulley, and having a custom OBD2 tune written. MSDS does make a header for our trucks, but the factory manifold is essentially a cast header, so I'd be surprised if you saw real gains from a header install other than your wallet and truck being lighter. If I remember correctly, you're in the Vegas area somewhere, so removing the clutch fan, and reducing cooling might not be a great idea unless you also get the tuner to lower the trigger temp for the factory e-fan. You can do the tuner without removing the clutch fan, but you really shouldn't remove the clutch fan without a tuner.