First thing go way down in air pressure, like 20 pounds and see if you like it. That is free, but will cost you a little gas mileage. When you tow or carry a load you should raise them back up.
[COLOR="Red"]I would not recommend doing that, 20psi is way too low.. remeber the ford Explorer mishap? Thats an accident waiting to happen. [/COLOR]
Do not get entry level Bilsteins if you don't like a rough ride. I think you are in a bad spot, because if you go for comfort I doubt you will like the way your truck will respond especially around corners with those 37's. I might look at getting some type of air bag for your front coil to soften the ride or remove the coil all together and go with a dual bag setup, and stay with firm shocks. I think most of these are for a solid axle, but I would search for something like this. You also will be able to find these for your back for sure. I had your generation truck a long time I ago but I forgot the front suspension setup, and it was a 2500 anyhow. This is the direction I would go though, maybe do the back first because you can find those for sure, and see if it helps.
An air bag and a coil will do the same function, so another option is to find a softer spring. The difference is you can adjust an bag at will, but your stuck with the coil. I would try to find a bag for the front, if not possible I would get a softer coil, but don't get softer shocks, this you would regret.
Being a 2004, he has torsion bar front suspension unlike your 2010 with coils.
If you were going to stay with changing shocks, find a dual reservoir adjustable shock. If you go too soft you will not be able to turn for chit. I had soft shocks on a Bronco and even though the shocks I bought were too firm, I would rather deal with that then dealing with a soft shock will going around corners, or even if you have to steer fast to avoid something, you will just be upside down.
Looks like about 300 bucks for the rear.