Most RVs use the double-DIN size in-dash. The trick will be finding one with RV-specific capabilities. The Kenwood DNX-775RVS is a double-DIN, in-dash unit with a 6.9” touch screen and RV capability. It has RV GPS guidance capability, but runs about $1,500; pretty steep for a 0.9 screen size increase.
A far simpler solution is a standalone GPS like the Garmin RV 890 (8” screen) or RV 1090 (10” screen) at about a third the cost of the Kenwood.
I don’t believe the Alpine unit you reference has RV GPS capability (setting height, width, length, weight, etc.); just auto guidance. If that is not important to you, then the Alpine may be sufficient for your purposes.
TJ