3rd Gen A.R.E. Z Series questions

I picked up a used A.R.E. Z Series shell last week and have afew questions that I have not been able to find the answers to with my search skills; they are probably out there, but I have not been able to find them. So, if ya'll could help, that would be great and I would appreciate it.

I have (not installed yet) Cali-Raised bed stiffeners ( I have read some of the "are they worth it/do they really work" debates). Can I install the bed stiffeners with my shell on the truck? I picked them up used but new in the box for half price and figure it's worth the peace of mind and can't hurt even if not really needed.

When I went to pick up the shell, it was already off his truck and the shell itself was in his storage unit. He was pulling the wire bundle off his truck when I got there. I just bagged it up and moved on. Last night, I removed all the wires from the loom to clean them up. There were 4 20' strands of different colored wires in the loom that were not connected. I have the factory plug and the hot seems to be the only one that runs the full length. I can't seem to find an all new wiring harness or a how to wire it diagram. Can anyone point me in the right direction? At this point, I figure it's probably best to just get a new one with proper wiring directions. The shell has LED brake light, LED interior light, and remote lock/unlock with the factory fob.

I am going to put a new gasket on it; the one on there is terribly dirty and rolled up when we were putting it on my truck with just the 2 of us. A monsoon like storm was lingering and I just put the clamps on and headed back home. What is the recommended best gasket to get?

Thank you for helping me out,
Katie
Gaper - 2019 TRD OR DCSB Cement

 

Would you mind sharing the answers to all the questions listed above? I'd like to assume that you have the topper installed at this point, and am in the same dilemma that you were in when you posted this! Thanks