Some observations:
You have not purchased either the truck or the trailer. This is a perfect opportunity to match the two with no regrets.
Money is clearly not an issue. The Ambition is a high end trailer, more designed for full timing, and a loaded Denali certainly isn't cheap.
So, it would make sense to spend the money smartly and buy a truck that can handle your trailer fully loaded. To handle the fully loaded Ambition pretty much takes a dual wheel truck. But, there are lots of really nice, decent size fifth wheel trailers in the 16K GVWR range that a 3500 SRW truck can handle.
