Moped Army

Hi ive been to scooter shows and ive always wanted one. im in vegas so having or getting a license to me is nuts so i want a 50cc it all i really need anyhow i want either a vespa or a lambretta nothing newer than 1980. where do i look to buy? and in my search all ive found is 150cc and up not much 50cc with in price and workable condition i want. i found one that says was a 50cc but kitted to a 150cc can you take a 150 and kit it down to 50cc if so how? just help me please. any tips or advise point me in the right direction.

Cheers