Do i need a full set or will just front or rear do the trick for a smoother ride?

 

Control arms won't necessarily give you a smoother ride. They fronts can help with caster which helps with flighty steering. A smoother ride is the result of your springs and shocks.

Some will say that the joint in the control arms will make a difference. I really haven't been able to tell any difference with varying control arm joints though.

 

Thanks bud

 

I thought moving from stock arms with 120k miles on them to rock krawler arms would be a huge improvement, it wasn't. I was kinda disappointed as I had it in my head all my bushings were toast. They were pretty damn bad but the ride is the same if not a tad worse. The steering is slightly better with more castor but nothing significant, the slight vibes I had from my pinion angle off with a cv shaft cleared up though.

 

The Krawler joints are nearly metal on metal with almost no give to them.
They will give you a tight, strong, no bind connection but don't expect them to ride better then a factory joint. The metal cloak and synergy joints offer a more comfortable and noise free ride but will always be in some kind of bind when flexed. I have not run the synergy but I can feel the joints compress and expand with the metal cloak. Ride feels a bit spongey to me. Note I came from running heim joints which have no give at all, very solid and can be noisy.