There are great, personal breeding accounts of both Naja and Oxyuranus in a favorite book of mine: Venomous Snakes-Snakes in the Terrarium by Ludwig Trutnau. Some of the info is a little outdated but still stands true today. Also ask breeders of cobras,etc. whom you see advertising are usually quick to share their stories about breeding practices. In regards to your question I saw on the SHHS page: checkout precisioncaging.com for premade trapboxes designed for venomous. I got two from the guy this last month and they work well.
Good luck,
Drew.