I am in the construction biz as well. I use a Bak Flip G2 Hard flip back cover.
I keep my tools and necessities in the bed using containers buckets and milk crates.
I unload my tools and stuff as required when I hook up the 5'er.
Because the stuff is in milk crates I can load/unload pretty easily/quickly
The cover flips back out of the way and does not interfere with the hitch.
Its not ideal but it works well enough. Been doing it that way for 6 years now.
My tools and stuff are secure enough to keep honest people out when the cover is closed and tailgate is locked.
19'Duramax w/hips,12'Open Range,Titan Disc Brake
BD3,RV safepower,22" Blackstone
Ox Bedsaver,RV760 w/BC20,Glow Steps, Enduraplas25,Pedego
BakFlip,RVLock,5500 Onan LP,Prog.50A surge,Hughes autoformer
Porta Bote 8.0 Nissan,Sailun S637
Correct Trax,Splendide