Your camping trailer, is small, lightweight and has one axle. Your model has 945 pounds of cargo carrying capacity.
FW tank is 16 gallons.
Pounds Cargo Capacity Left
Cargo carrying Capacity (from Jayco Website) = 945 lbs.
FW tank = 16 gallons x 8.3 lbs/gal = 133 lbs
2 20 lb propane tanks filled = about 75 lbs.
Group 24 battery = 45 lbs x 2 = 90 lbs.
Etrailer hitch (as in Mr.Scary's post) 100 lbs.
Thule 2 bike hitch mount rack 50 lbs
Rear bumper ???
Assembly for holding propane tanks ???
Assembly for holding additional battery ???
Food, clothing, cookware, camping supplies ???
Be sure to carefully check all the things you are planning to add so that you don't overload it.
I suggest you load it up with food, clothing, all camping supplies, propane, and water as if you were going camping for a weekend or week and get it weighed at the scales. Do this before you make any more proposed modifications. You may not have very much to work with and still stay under your gross vehicle weight.
Then decide which additional modifications (if any or perhaps all) you can make and still stay below your gross vehicle weight limit.