Hello, to all who have bought and used this hardware kit to build a murphy bed I was wondering if you could tell me what species of wood did you se for the internal frame of the bed? The instructions say a few different kinds and I am not sure what I should use? I would obvioously prefer to use a cheaper wood for the internal frame and save the more expensive woods for the exterior of the bed. That being said, I do not want to jeopardize the strenth of the bed in an effort to save money.

Thanks in advance.

Derek