Always be on the look out for sales. I agree with the SK being good.
If you want to do it over 2 days, I would split it up do the box one day then the cab. Luckily there is a good break in it, the worse part for me always seems to be the hood, bumpers, and fenders. So maybe start on the box and try some things out and get a good feel for things, they are good straight panels. I have a Dark Grey 2017 Silverado, and the day after I got it I used my SK then use glaze, then sealant over the top. Truck looks amazing, even now after 6 months it still have the very slick looking color, but it is starting to get to the point where it needs it again.