sospa jnr has a pizza business...Pizza Boys and been on tv.
They use specially prepared wood that is safe for use in the wood burning ovens. Clean burn with no toxins. Bought bagged from a supplier. Not cheap but a must have. The oven takes about 20-30 mins to get hot, about 500deg.
A mate has a small stove he uses in winter to warm a greenhouse. It's outside and warms water for pipes inside.