I'm getting a 2yr old redfoot. I'm going to build an enclosure but am unsure of a couple things. would 4ftx2ft be big enough and I'm thinking of covering half of the top with glass for humidity and a heat light on the open half. does that sound ok? or should it be bigger? or do I have to cover the top at all? I'd rather leave it open. I've seen lots of designs. I appreciate any advice