I've been using plastic closet rod holders from the hardware store, Lowe's, Home Depot etc. You can silacone them to the glass and they'll easily hold an adult chondro or emerald. Below is a picture of one of the enclosures. Perches are made from hexagonal PVC rod cut to lenght to fit snugly between the holders. This method also allows you to remove the animal while it is still on the perch making life a bit less stressful for you and the snake. Hope that helps.
Rico Walder
Signal Herpetoculture
