This site (although not a dating site) is not a bad place to start.
Lots of really decent human beings (female and male) hang out here, and many of the men (once you sort out the photoshopping/thieving riff-raff) have large and gorgeous cocks.
Add that to the intelligence and insight often demonstrated here, and the choice of compatible partners is far better than it might be in other places.
The biggest (no pun) problem is geographic separation -- I'm sure the reasons so few couples (gay and straight) from LPSG ever actually hook up are largely (no pun) due to geography.
I never would have thought in a million years that I would move to another country to be with a man. I certainly wouldn't be doing it for "just" a big cock. But I met my soul-mate here, on a site where many of us are more truly ourselves than we are in the real world. And the emotional, intellectual, and sensual connection...the deep, resonating understanding of each other that we have...made us both willing to move mountains to be together.
My point remains, though...would I have found this awesome human being (who just so happens to share most of my interests and have a big cock) at Barnes and Noble?
Most likely not.