I have no issues with rancho shocks or teraflex leveling kit. I have a buddy that runs the teraflex leveling spacers and endlinks on his JKU with good results. I run rancho rs9000 shocks and teraflex 1" front spacer on my JKU. I have been pleased with the rs9000's positive impact on the ride, smoothing the jiggly stock ride.
I'm not a fan of the rancho 2" lift springs. I first ran that kit on the JKU and the front springs are significantly stiffer than stock. The free length is the same as stock but installed provide 2.5" of lift. I much prefer the ride and handling of the stock spring with a spacer and rancho shocks.
I'll give you another option to consider. Synergy makes a 1" JKU lift spring that has a spring rate slightly stiffer than stock but not as stiff as the Rancho spring. Expect ~2" of lift depending on how heavy your JKU is. The free length is far longer than stock or Rancho, and they're known to provide great flex with the appropriate length shock. A set will run you $380 at Northridge with a discount code. You could also opt for the 2" starter lift which includes springs, bumpstops, brake line extensions, swaybar endlinks, etc. for $675
