I have a 25 HP billy goat mounted on a 12 foot dump trailer and the amount of air flow is insane. I really think you are going to want to re-think your set up. IMHO your loader is way too big for a 6 foot pick up bed. I went from a 16 hp to the 25 hp and the increased compaction and shredding is night and day. All the time you save loading is going to be wasted unloading by hand. Its a solid brick when full.
Not trying to get you down I think you just need to seriously consider getting a dump trailer/truck to run the loader into. Depending on the size of your properties you could be filling your truck every hour of so.