Randy, I'm planning on using the suggestion to get the kit with the mini mag mount (for the truck) and then separately order the larger spring mounted antenna to place permanently on the TT.
I think I want to use a semi-permanent mount on the TT in a relatively short position on the roof to have good clearance but still have the ability to quickly reposition it on a taller rod/staff for those more remote locations where height helps, per Nutman's feedback.