I have wheeled with a guy who has the coil kit on his YJ. It seems to twist up really good.
As for the cost of the Warn kit vs. SOA, if you have to pay someone then they cost close to the same. The Warn kit goes for $1800-2000 and it's generally around $1000 labor to install. Most people think the SOA setup is a lot cheaper but if you do all that you really should do, the cost of the SOA approaches that of the Warn kit with install.
If you can do the work yourself, all bets are off since you're probably also capable of fabricating parts (eg. tie rods) from inexpensive raw materials.