Yes, I called the company just a couple days ago, since a friend was going to capitalize on the buck a gallon sale, and they said only the bottom is tempered.
As for the HOB
overflow, I don't think I said that- I would use a Glass Holes Overflow though. That's what i have on my 105-
I drilled for return, but my tank is rimless, and meant to be viewed from the top as well as the sides and front. If i was using a standard tank, I would not have drilled the return.
So, you could either do one of these overflow boxes, or a simple 90 with a strainer on it-