That sketch reminds me of the awesome engineering (gut feel to be honest) that I did for my 01 X. I home fabbed them and put them to the test. You see that little angle that he has against the frame... I bent that upon nice contact with a rock on the Golden Spike. I know I used my gut feel and used 1/4" angle but I did not engineer it and it failed.
On to my real comment... unless you have true calcs behind your sliders, and real meaning that you know it will not be the weakest link on your set up, then go ahead and fab up some sliders. It will probably only save you $100 in the long run. That said, I have my sliders on order from Calmini.