Extended Receiver Hitch

So we have a 9.5 hard side Shadow Cruiser on our 8' bed 04 dually. Want to tow open pit car trailer with FJ Cruiser. FJ weighs little over 4,000# and trailer is steel. Don't know about tongue weight, trip to scales in order I would imagine? The camper extends 1.5'past bed of truck but also had those pesky "fins" the 90s models have. Suggestions on length of stinger for receiver to clear corners of camper on turns would be nice. This truck has hauled some heavy receiver hitch loads in the past 12 years but not with 3000# in the bed and most definately not with any extension. Is this another TORKLIFT, TORKLIFT, TORKLIFT deal? It would just figure as we've had one thing after another depleting our traveling funds in the last couple months. I'm all for flat towing the new Chevy 2500 4x4 as that is an option, just not on DH,radar yet, but that's not cheap either. Oh dear, what to do, decisions, decisions. Sorry didn't mean to hijack the original post but enquiring minds need to know.