One of my friends just bought a set of springs from National Spring for his CJ-7 and is VERY disappointed in them. He ordered them for 2" more lift than he had and they came with 4.5" more lift (even after breaking them in), they ride bad and have less flex than his "off-the-shelf" lift springs that were on it. He paid around $1,300 for them.
They also sent him the wrong u-bolts and stuff the first time around. They said they would "fix" the current springs but he would have to put his Jeep up on blocks for several weeks while this would happen and is very hesitant that they can "fix" the springs.