Your set up isn't at ride height so none of these comments are relative-----you need to make up a pair of tubes the length the shock will be at ride height and work with that----------- and generally those kits are set up to be put on the axle housing with the rear face of the shock mount at the same angle as the face of the housing where the punkin bolts in---------

As for the angle with the frame----put the mounts at a width as wide as you can with the inward leaning of the coilover at a reasonable angle and still as wide as you can---the angle with the frame of the lower link doesn't mean much as long as its reasonable with regards to triangulation of the axle tube and the upper link----

What does concern me from your pics is the upper cross bar for the coil over mounting---it carries the total REAR weight of the vehicle and looks like the twist it will get from the load plus the bending from the weight might cause a failure-------