2x herbies will definitely give you the most flow, but may not be entirely necessary imo. I would just use two durso type standpipes with valves and two emergency drains. Then run the returns over the back as mentioned before. If you find yourself needing higher turnover/more flow then just convert one or both of the e drains to the herbie configuration like wolfman suggested.
You dont need to buy an overpriced kit, you just need some lengths of 1" pvc, a 90, a tee, a cap, and the valve--probably $10-15 from hardware store. The emergency drain would really just be a length of pvc pipe. When building the standpipe, i would cut the drain to sit 2-3" under the waterline.
I believe those tanks use tempered 1/2" glass though im not sure. Should be plenty sturdy as long as its braced well. I would use caution if youre gonna be placing heavy rocks or other scape in the tank though.
I was hoping to have the top really clean and get the return in the tank. I wonder if 1 herbie would be suffecient. At any rate, I am definitely planning on building my own. I'm building the stand right now out of 2x6's. I measured the glass, it is 12mm (slightly under 1/2"), I don't think it is tempered, I will check with some polarized sunglasses.


