thanks idlegossip. I phones up StyroMax this morning and they were quite helpful. As mentioned by JPH, they provide floors/tops OEM to Aussie Swag and Rhinomax. Cost is $900 for 2.5m x 2.m panel with 2mm fibreglass on each side. I am going to be taking my tent off for a couple of small patches this weekend, and likely to take the metal support frame and floor/top off next weekend. I can then disect it to see how it is constructed and fits together, and will then go shopping. Will likely go for the StyroMax product however I want to first see how the metal support frame is mounted etc. Will post further as I progress. Out of curiosity, what is the support frame made from on your Spacematic ? Is it gal steel or aluminium?
In regards to using bonded styro panel for a floor/top for your camper noacastrianlad, the company l work for uses the same blue foam as StyroMax bonded between layers of Aluminum. The foam is called 'styro' but don't confuse it with your run of the mill fruit box variety, at 25mm thick It's amazing just how strong the foam is when bonded and pressed between cover sheets, there are two things I would consider if you want to use this type of product.
The edge of the sheet needs to be completely sealed against moisture. If moisture gets in the bond between the foam and sheet there is a chance of de-lamination not to mention the added weight that could be trapped as a result.
The mounting points of your support frame may need to be altered to spread the pressure across the panel when it is being used as a floor. May be worth talking to the manufacture/supplier as to their thoughts, or research how the previously mentioned camper trailer companies using this material in relation to support frames.