making a cage+safe paints/plastic coating?

i was considering making two pretty large cages out of wood and mesh wire soon; one for my rats, and one for my mice. however, i was wondering if it's alright to paint the outside of the cage (the wooden parts?), and if that's ok, what paint is the safest? i also have heard many people mention powder coating for the wire. where should i look to get this done, how much does it cost, and are there any other options? thanks!