build help

Sorry in advance, I feel this might be a long post by the time I am through with it. I realized I really missed having a vivarium. Although mine will sadly never see frogs I have started the purchasing process of a new one! I made a few tanks a few years back with probably not the worst but...

Can someone direct me to a build which uses concrete as I would love to give it a go. Also, does anyone from the UK know where to get egg crate for a false bottom? Thanks