The ADJ lowers are to compensate for the loss of wheelbase. When you lift the jeep the front and rear wheels will move toward each other slightly. Adjusting the lowers to be longer compensates for this. The ADJ uppers are meant for only adjusting pinion angle and alignment issues for drivability.
In a perfect world, you would be better off in the long run and prevent yourself from replacing parts that you have already upgraded by buying all 8 control arms. The same can be said if you expect to do much off roading and with the decision to run the JJ ends. The JJ ends are also much more durable than most poly or rubber bushings found in control arms. They are also rebuildable obviously.
If you absolutly have to make a decision and choose rather you only buy the upper or lower control arms, I think I personally would choose the uppers. As for the brand you are thinking about going with, I cannot comment. I have not ever heard anything about them. What I do know is Currie and Rokmen (my choice if I were you) make a set of control arms that are hard to beat and are very durable. The Rokmen are much more stout and beefier than most any other brand you will find.
In a perfect world, you would be better off in the long run and prevent yourself from replacing parts that you have already upgraded by buying all 8 control arms. The same can be said if you expect to do much off roading and with the decision to run the JJ ends. The JJ ends are also much more durable than most poly or rubber bushings found in control arms. They are also rebuildable obviously.
If you absolutly have to make a decision and choose rather you only buy the upper or lower control arms, I think I personally would choose the uppers. As for the brand you are thinking about going with, I cannot comment. I have not ever heard anything about them. What I do know is Currie and Rokmen (my choice if I were you) make a set of control arms that are hard to beat and are very durable. The Rokmen are much more stout and beefier than most any other brand you will find.