The 3.5" SF kit works fine, of course not a well as the long arm. Their are a few items I highly recomend.
1) If your just getting the straight SF kit, upgrade the upper arms on both axles to adjustable. You will then be able to adjust the pinion and caster angles much better.
2) Adjustable front and rear track bars.
3) SYE kit w/ HD Tom Woods shaft.
My current set up has all adjustable control arms, 33" tires and a SYE. The adjustablity has been great. Very glad I did all the upgrades.
One customer installed the SF kit and has vibs due to no adjustabilty. I think their going to do the upgrades now.
Check with Jason at Red Rock 4x4.com
he really knows his lift kits. They do a lot of product testing, what works and what doesn't.