Go online for the installation instructions for the ones you are interested in and see which one mounts the easiest for your vehiclel.
NOTE; I am not responsible for typos, poor grammer or misspelled word !
04 Itasca, Meridian 34H, 330 Cat/2003 CR V Toad
1933 Ford 3 Window,as seen in Bye Bye Birdie
Pvt. E1 Retired, Shadow Hills,Ca.