Down low is my preference, but it only lets my passenger see the screen. I can get the wifi module so i can mirror the screen onto my phone and then have it mounted somewhere in my line of sight.
The Panavise in dash brackets would be my recommendation. They are custom designed for the truck and work slick. http://www.panavise.com/pdf_indash/75107-315.pdf
Just for grins - hold it above your rear view mirror... I mounted my GPS in my SxS up there to keep it in the shade and easy access. Plus less likely to be mis-appropriated since its not it clear sight from outside my rig. Look into RAM mounts.. They're great!
so for shits, grins and education i know i gonna get bashed here. i see all those offroad Lowrance units discontinued. not that it doesnt add value but what is the new shit that put that out of biz ? or why no more Lowrance for sale in the offroad models ?