There's two ways to approach ordering a new truck.
One, is if you are a Costco member, you can use the Costco website to build your truck and VERY IMPORTANT: contact the salesperson that Costco has listed on their site - SPEAK TO NO ELSE!
The dealer's Costco authorized sales rep will first check all the dealers nearby for your truck and if it's not acceptable to you then they will go through the order list and get you what you want.
The order list is very detailed and deserves much study since each upgrade model will contain lower models features as "standard" rather than options.
The other method (not via Costco) is to contact the fleet dealer at the dealership. Don't deal with the auto sales people. . .they don't know squat about true truck specs.