The 15021 you referenced is a replacement for an Atwood rooftop unit, and based on the research I've done you have a 13.5K BTU Coleman Mach AC unit so it won't be compatible.
Instead, what you need is the Furrion Chill HE Replacement RV Air Conditioner for Coleman Setup - 13,500 Btu - LED - White # FR82PV. view full answer...
For your 2007 Jayco Jay Feather Sport M-186 I recommend going with the Fastway e2 Weight Distribution # FA92-00-0600 as it is a better match to your weight specifications than the Fastway e2 Weight Distribution # FA92-00-0450. Your Jayco has a dry tongue weight of 370lbs with a GVWR of 3,900lbs. Since most of the weight is added to the front of your camper with the battery, propane and storage compartment in the front you will easily exceed the 450lb max tongue weight rating on the e2 #... view full answer...