Anderson 5th wheel Hitch install

[ngarc]

We have a completion date of June 2022 for our 5.0 TA.
I have pulled bumper pulls before but never a 5th wheel.

Wanting to go with the Anderson Ultimate hitch and were wondering about the placement of the rails in the bed. Our vehicle is a 2019 f150 with the 5'5" bed.
Is there a standard placement of the rails over the rear axle or is there some leeway?Just wondering because the information on the Escape website gives differant placement distances from the bulkhead with examples of turning radius and clearance of trailer from cab corners.
Would any reputable hitch installer know where to place the rails?
Also does anyone know of an installer in or near Sumas Washington, especially one familiar with the F150/5.0 set up? I know there is one near Chilliwack and would consider getting it installed there, but not sure of what the border situation will be when we pick up.
We live in Illinois and could also get the hitch mounted here at home, just want to make sure it is properly placed in the bed for best turning radius.
Total newbie at 5th wheels so any advice would be greatly appreciated.