The 30a will do the two panels lying flat. You would only need the 40 if you got more panels, or if you tilted the two panels, and that would be on a different RV from that van, unless you set them up as portables on the ground tilted up facing South.
You probably will be fine with just the one panel unless you intend to use solar in the darker and colder half of the year. Depends on your daily AH usage.
You might do a little better financially to just get the 20a Eco-W MPPT controller for the one panel and then if you ever decided to get more panels, maybe with a different RV, who knows, then choose a different controller for that set-up, which might not be the Tracer--might be other choices you like when you have some time in with solar, and more products appear in the market. Need a good crystal ball. :)
You only need to see the display on the Tracer controller when first setting it up. The default charging profile is suitable for many folks so you don't likely need the remote to customize its charging profile.
It is set to get to 14.6ish Vabs, holds that for two hours, and then drops to Float of 13.6 ISTR. Works for me, here, in the summer.