I'd go with the RK kit, the JKU springs will give maybe 1/2" or so. Like you said too, you can add arms and springs later.
Take it from someone who has gone from stock > JKU springs > JKU springs and spacers > Rusty's springs > Rusty's spring and spacers > RK springs. Just get the ones you want and save the wrench time.
07 X - Flame Red - 6 Speed - 5.13s - 37x12.50 MTR/Ks - ProComp 7069s 17x9
RK 3.5" X-Factor LA - WTOR Hydro Assist - Rubicon Axles F&R - Trussed & HD Brackets
PSC Flares, OR-Fab Front Bumper, Genright Rear Bumper, Poly Sliders w/ PSC Armor