Lets look at the numbers.
As you said, your GVWR is 9900lbs.
Your GCWR is 20,000lbs.
Because you have a Super Cab and not a Crew Cab, that helps since the truck is lighter.
My 02 F250 PSD CC weighed 7200lbs with full fuel and no passengers.
I would say your truck weighs around 6800lbs.
So, 9900-6800=3100lbs available for passengers and pin weight.
20,000-6800=13200lbs for total weight.
You might be able to get a LE3105 or 3305.
What do you plan on hauling in the trailer?
2006 F350 Tow Boss pulling a 2006 LE3905 Weekend Warrior. Inside Warrior: LS1 Powered LT 5 seater. Go baby Go!!!