Eric, I almost went with that solution at first as I wanted that system bad, but when I spoke to the manufacturer of my frame, they told me they would void my warrany if I used that system (Lippert). They said the pin box was not designed for side loads like that. I have heard that they since changed their design to accomodate that but that was too late for me.
BTW. . my slider was $1600 delivered complete.