I just went to an adjustable because I hit 6". I ran a factory one until that jump from 5". Adjustables are pretty spendy, but they do allow for a little more articulation because of the heim joints. At 4.5" I'd just get a factory one. They are under $100. Scrap yards are full of them. Just pop them off the XJs they have until you find one that has a good end. What is wrong with the adjustable one you have on there ? Don't let the steering scare you away either. It is pretty simple and straight forward. Like the one guy said just have them do the balljoints. See if they will allow you to supply parts and shop around if they do. Some shops do most don't though. I'd go Spicer or Moog BJs. Good Luck !