The "BTF Triangulated Lower Link Mounting Kit" was designed to simplify 4-linking front suspension systems although it could be used in the rear also.  The kit consists of 4 plates.  It is all you need for the axle side of your 4-link.  The plates are laser cut from 5/16" high-strengh steel plate.  The lower part of the plates are bent in at about 20 degrees so your lower links will attach to the chassis in the middle and your upper links run parallel to each other and attach to the chassis at the frame rails.  The holes are cut to 1/2" so they can be drilled to whatever size you need.