You could get an orchid growing on top (any one will be happy I think!), use spag media and then get few fern peices in one of the bottom holes. Ferns grow like weeds (trust me, I constantly pull them out of my pots and baskets!) and you would soon have a fern, orchid pot.
I love the idea of plants coming out of the holes! That would be very interesting looking and a GREAT excuse to by more orchids! Whatever you decide to do, please, please take pictures! I would love to see the finished project! Good Luck!