I'm not aware of a .5" spacer on the market. An OE rubber spring isolator/insulator is .5", I recommend a new replacement, and not to install without one, new or original. OME makes a poly hard durometer 10mm/.395" shim/spacer, most other spacers are .75" and up, made of softer polyurethane. Place the rubber insulator above the spring, poly between insulator and body. Since you have a rear wheel on the carrier forward rake won't be much, but if there are plans for an aftermarket bumper and/or winch, add a .75" spacer to the front. Spread KY personal lubricant on the front bump stop shaft to make it easier to R&R the insulator. Be prepared for 1.5" to 2" front bump stop extension.
For the rear bump stop extension, OME makes a
20mm/.789" spacer that will cover that length shock, or add a stack of washers for much less cost.
BTW, store/stand Rancho shocks upright. I have a blue Jeep too, and I thought the white shocks with red boots looked great, at least with polished wheels. I vote to keep the shocks original appearance to start, just remove the decals. Springs are a lot of work to R&R, shocks not so much.