Personally, I have very much enjoyed playing Shaco as a support. All of his abilities provide some kind of utility, so even if you are behind in gold, you can still make it up with raw skill. Usually, however, this isn't a problem because I typically find myself ahead in kills as Shaco early game. He has free wards, an easy getaway/bushcheck/chase Q, a slow, and an ult tht can really distract the enemy if played convincingly and take a lot of pressure off of the AD.
Though so far, I am the only support Shaco that I know.
Finally, as far as AD/AP, I don't like AD early game, and I [really] don't like AP late game, so I almost always do a hybrid. Build AP first, AD later.