Underthings at www.underthings.com has seen through mesh and fishnet underwear for men. They will make any item in mesh or fishnet, just for the asking. I've bought several times from them and have always been happy with them.
Why look for and try to find a place that carries men's see through underware when you can go out and find exactly what you want with women's lacy lingerie and it is readily available?
Yourprivates.com offers customizable underwear...you pick the style you like, and then the fabric - net, lycra, slinky and others. They manufacturer it and send it out in just a few days. Check it out.
At Amazon.com, you can find a wide selection of panties and thongs for men.