Try these for a start:

http://www.rcstore.com/rs/general/plans.asp?catego=PL

http://www.rcmmagazine.com/e/env/000...ore-plans.html

Other magazines have listings also. I have built from RCM plans and they are of high quality as I am sure are the MAN plans. Others can give you more sites I am sure, these are the two I can think of in a hurry.