Leave such steering stabilizers off your Jeep. They only make the steering system work harder. Good return-to-center is a result of a good alignment with sufficient Caster angle and proper toe-in.
DW is caused by a combination of things, and NEVER by the steering stabilizer. A loose passenger-side trackbar bolt (2002 and older 55 ft-lbs. 2003 and newer 45 ft-lbs), improper tire balance (they must be PERFECTLY balanced), or something else being loose.
First get the toe-in set properly to between 1/16" and 1/8" per the easy instructions at http://www.4x4xplor.com/alignment.html
Then tighten the trackbar bolt, then get the tires perfectly
balanced. This should get rid of your DW. If not, there are a few more things you can try.
So far as the desired Caster angle goes, it depends partially on your tire size. Stock size tires, 7 degrees is about right. Around 5.5 degrees for 33" tires, 4.5-5 degrees for 35" tires. The exact Caster angle is less important as it is to simply have enough
caster angle. Don't be trying for 7 degrees per the factory specs if you have bigger than stock tires.