The original shocks are Boge and are still available. Bilsteins will work but they were a little too stiff for my taste when I installed them on my dad's xj-s several years back just fyi. It's an easy DIY job. The front ones are especially easy as they are independent from the coil spring. The rear is a little tougher since there are 4 and you must compress the coil springs. I don't see how any independent shop could mess it up.

 

KYB Grey shocks work well, I ordered from rockauto. Not rock hard but enough to give the car a smooth ride while still allowing for extremely nimble maneuvering. If looking into suspension also assess the bushings all around, jacking the car up and letting it hang will give you a good idea. While redoing my suspension with KYB shocks along with superflex poly bushings/subframe mounts a number of failing bushings and mounts were discovered which contributed to steering jutter, and sloppy handling.