They got it right, no offence here, just an heads-up, myself I don't plan to lift it, just went from the 29' to 31' tires, and that's enough for me with what I'm doing, because only with this set up, I'm going to fishing spots where almost nobody would go. But I can tell you that I scraped that Hitch a couples of times, and I'm not doing any extensive 4x4 (at least in my mind). So my suggestion about getting a longer ball mount than a longer receiver, up to you.
About the security chains, I must have been confused about the picture of the Hidden Hitch, but I don't see any hook-up points on this one, must be me
(too much beer today).
Here is a picture of it. (I know don't jump about my spare tire, I haven't upgraded this one like my other tires)
Also I don't know anything about your trailer, but I raised mine to get about 11'' of clearance, and with the drop I have on my ball mount, my trailer is still leading a bit upwords (higher in front than in the back, may be by one inch)