Deciding the materials for a grow cabinet

Hi there,

I'm trying to decide which wood I'm going to use to make the cabinet. This is what I found so far:

chipboard
PROS: is cheap, comes in white so no reflectant needed,
CONS: if it gets wet it won't last long (although the melamine helps with this)

plywood
PROS: more resistant to heat and humidity ?
CONS: expensive, it has to be painted white

MDF
PROS: more resistant to heat and humidity
CONS: heavy and difficult to work with?, the external color is an ugly dark brown, has to be painted white

Can anybody give an advice about which wood to use ?

I would go with the ply-wood, its fairly durable, easy to work with.