Moped Army

Hey there! question is,what to buy for nightly ride from work,
some semi steep roadways to climb,about ten blocks worth
Have to keep this at 50cc or less, looking at used models from late 70's to mid 80's.Like to have unit as bicycle like as possible for lifting onto bus rack sometimes on wknds
Open to any and all suggestions Want moped that parts readily available if possible. Thanks from Bothell,WA