I am not big on Fontaine, but they are a good trailer. With you hauling 65K you will never know the difference between the 51ton or 55ton. They can handle abuse pretty well. I prefer Etnyre and XL, but Fontaine will work for you just fine. I would not be the least scared of a Fontaine with 65K. Their flanges are T1 steel like all the other major manufacturers. They use 50K structural steel in the webbing which isn't a concenern, XL, Trail King, etc. use 80K in the webbs. I have learned is basically is no difference. What to watch out for are Eager Beavers (no T1 flanges) and the Witzco's, etc.
To answer other people's questions on these threads, Fontaine and Liddell are the same. Mitch Liddell (died in '05) who owned Liddell and Birmingham sold out to Fontaine in 1991 and signed a "no-compete" clause not to compete vs. Fontaine for 7 years. In 1998 he came back and started Liddell again and got Entyre to build most of his trailers, but with Liddell's design. That is why Fontaine and Liddell look the same...because they are. Liddell is still in business but barely hanging on by a thread at the moment.
Etnyre bought out Hyster trailers in 1989 so Etnyre owns Hyster's designs. They hardly use any of their old designs because they are "out-dated", but Entyre bought them out to get started in the lowboy manufacturing.