1. Topper
2. Buy the one that makes you happy, especially if you're keeping the truck for a while. That said, the second you write the check, you own it and it's essentially only valuable to you, especially if it's color matched. My wife convinced me to buy one for my 2014 and I hated it through and through. When I traded it in on my 2018, the dealership told me I had to take it off and do something with it. I told them if they wanted me to buy the 2018 they were taking it or I was going to drive around back and roll it off into one of their dumpsters.
Needless to say, they took the topper.
If we were having this conversation last September I'd have driven to Colorado and made you one hell of a deal on the graphite metallic Leer topper I had.