In my travels I ran across a company with a CNC hotwire cutter. That is a heated wire for cutting Styrofoam blocks. If you need to cut a specific large shape from styrofoam this can get it done. It can cut a block about 8'x4'x4'. When planning what it can cut think a giant bandsaw with a very narrow blade. It cuts profiles defined in Autocad. While I was there he was making about a half size front
It is at Mizner Stone located at 1200 E Altamonte Drive, Altamonte Springs, Prairie Lake Pavillion, around in back. Talk to Cameron Hamel 407-790-1203.
I took a video of it in action but don't know how to post it.