You could go with the 70w sunpods and put some sort or grate or like you said pond netting over the top. I would have upgraded to a sunpod or a viper HQI, but my cats would have had a field day with an open top tank..
If i ever upgrade my lights ill go for the 3.24 nano tuners one (the one your looking at). For now everything seems to like stock, so no sense changing it.