American Classic Truck Parts U-SMR2155, used $25 and a picture. You can buy two of these, go to a junk yard or make them from bar stock (flat, not jogged, would work) and a shock mount (O'Reilly's 31001 or equiv). They are a very simple piece. The angle is given to you by the holes in cross member. Probably a dozen ways to provide a DIY upper mount. The exact location is not critical. Post in the wanted section, it's always nice to have the actual part if you can find/afford it.
The ones you reference may work even though the shock eye would be 90 deg from orig. But you can see how easy it would be to design your own and their price is about the same as two American Classic ones. Two DIY/somebody's bracket, design considerations: 1. Shock eye does not hit bed floor and 2.Shock tube clears rear cross member. Mock it before you lock it!
