Correct. Those are the ones you want for that much lift. For a bone stock van with the 5.4L, it will feel stiffer. But at least it won't bottom out anymore off-road. It's ideal on the V10's and diesels, or vans with heavy steel front bumper.
Stock length shocks will work with this spring. Any good monotube will be fine. I have KYB, but Bilstein, Fox etc are all good.