Suspension upgrades include: CHF, Bilstein Comfitrac shocks which are specifically tuned for the F53 chassis, trac bars front and rear, sway bars front and rear, Safe-T-Plus, and for the final touch add Sumo Springs front and rear.
The CHF (Cheap Handling Fix) if applicable should be first on the list.
Adding other components until ride comfort is met is a personal choice.
This link has some of the needed information to get started; http://www.irv2.com/forums/f23/cheap...fix-72335.html
Some people say the F53 chassis is also much better when traveling with a full fresh water tank.