CardiffDillon: You could try 'Othello' and his 12"er, he's London based but often travels to the US. For a West Coast option take a look at Ryan Holmes, listed as being 11". Both are featured in the male4malescorts link I gave earlier, just use the 'search' option.
There's also a NYC based escort called Joe 12 x 7, I have pics of him and his email address but I can't recall which site he came from.
In Florida there's a guy called 'Romeo' claiming to have 12.5", you can find him listed in the escorts section at
http://www.mansurf.com/
I haven't found any bigger than these.........unless you guys know different;-)
cheers
Dillon