You would want to refer back to the overall governing body on this one for the best response: http://new.usgbc.org/leed/certification/homes. USGBC developed the LEED standard and this page outlines all of the costs and considerations for getting a home certified. Yes, you will definitely need to have someone do the verification. However, I believe that they don't have to be an architect to be LEED certified. I know one or two people in my area (central California, US) that are LEED Professionals who are not full architects.
The same professionals would also be your best bet for locating any houses that have been certified. I would try contacting some Architecture firms and asking about LEED professionals. Another good bet, in my experience, is to look for activities/gatherings with an environmental leaning and asking about it there. I have found "Green Drinks" events to be a good nexus for this if you have one in your area: http://www.greendrinks.org/