oak or balsa wood oaks ur best bet if not use pine and coat it in varnish balsa is a little soft so u may not want to use it
De Havilland Mosquito was constructed mainly of plywood containing Ecudorean Balsa and Canadian Birch woods
I love using balsa foam for sculptures. It is very easily carved and extremely lightweight however it is a little messy. You can read more about it at this website: