TV Cap and Roof Rack Advice

[Explorer7]

I have a 2018 GMC 3/4 ton Crew Cab TV and I am getting ready to buy a cap for it. I am leaning towards a Leer 180, because I want the extra height.

We have two Native brand kayaks that we want to transport on the truck/cap. One kayak is a 14' tandem that weighs about 60 pounds. I have search this forum and I have not seen anyone with a cap higher than the truck cab transporting a long kayak. With this length, I believe I will need a rack on the truck cab and also one on the cap, correct? Will there be an issue if the front of the kayak is 5 or 6 inches lower than the back? Will it obstruct visibility?

What are your recommendations?

Please advise. Thank you.

[GMFL]

I do not have a shell taller than my cab, but I do haul all kinds of stuff on our roof rack.
Let me know what you figure out.