I have a 4" Z bend type, but it is welded on, and a 6" A Arm Lift. I will always go with a lift that doesnt require cutting the frame from now on. I am going to redo the 4" this winter put it back to original, and install the 6" Super Sport Lift. The A arm is great, never any problems, and with that type lift you get a new suspension, as far as Brackets, Front Spring, new arms..Spindle Lifts are cheaper, but have heard of many bending issues.
Go with an A Arm, only a couple hours and very well built, BUT, make sure the kit is AMERICAN BULT. There are some CHEAP CHINA MADE KNOCKOFFS for sale. BEWARE...