Colossi Al Colossione frameset | Retrogression
But that frame actually has less than what you need since it isn't drilled for brakes. You don't really seem to know what you want since porteur bikes are supposed to have baskets and whatnot. Maybe you should look here for some ideas:
http://www.bikeforums.net/singlespeed-fixed-gear/286515-showoff-your-townies.html
There are some kilotts in there.