I used one of my smaller Phalaenopsis which is planted at the back. I also finally planted my Cymbidium which I bought on a trip to Madeira- I'd neglected it pretty heavily leaving it in it's travel packaging for a few weeks so it's not looking the healthiest. Hopefully it springs back to life now it's in some heavily fertilized soil.
The glass vase was something I found on the street- the lamp part came in a job lot with some photography equipment. I think it might have originally been part of a photography enlarger. I changed the plug and the bulb and it fit's almost exactly to the vase. To keep it a closed system I also found a glass saucepan lid to seal in moisture to the whole set-up and stop the electrics getting wet.
My other closed terreriums are starting to really mature - they're growing little ecosystems of their own with molds and fungus blooming and then settling down. I'm excited to see how this one develops once it gets a bit older.