can use my Traveltrailer-tirepressure-calculator to be found in next map on my skydrive.
In the American English language setting it uses 10% tonge-weight, but you can give your own in orange small cell .
So calculate it needing maxload and pressure needed for that. the 9600lbs for the TT you already gave.
If you cant work it out give the tire-data read from the sidewall and I will do it for you.
Then you can use this in your further search, and see if you can savely go lower in the pressure.
Mind that an E-load tire needs a higher pressure for the same load then a D load tire. Also you are allowed to use 10 psi higher pressure then the 65 psi belonging to a D load. This is not the maximum pressure , but is called the maxloadpressure, Pressure needed for the maximum load, or as it is called in the formula sheet of the ETRTO about it the Pr=reference-pressure.