I found the best way when working in a home shop is to do a mock up and tack weld everything together.
I bolted all my mounts to the unibody, then put the rocker skids up on jack stands in the location I wanted them. I then tack welded the mounts to the rocker skids so I'd be sure everything would line up. Take the whole thing off and weld it up. Generally it's pretty close that way.
When I mounted mine, I used jack stands and an extra person. Then I did the corners and drilled and mounted the rest inwards.... it wasn't a walk in a park, but it wasn't that hard either....
Also clamps works good if you don't want to have ot do talk welds.
well I welded everything up then drilled my ount hole. then I put them on the tranny jack to hold into position while I marked were to drill on the frame! Needles to say the drill must have walked!