I ordered a custom 36x36x24 rimless, 3 side starfire (3/4" glass sides, 5/8 tempered bottom and overflow) from Miracles last november. Love the tank. Fortunately I have never had to use it, but good feedback on customer service as well if you look around online. I priced a few builders, Miracles was not the cheapest, but about average for the glass. Of course then there is shipping, build lead time, etc. to be considered.
One thing I was not crazy about was the communication from them. For an $1800 purchase I would have expected a couple photos, cad design etc. They built off a verbal description over email. To be fair, I only asked for photos of the overflow build etc. (asked twice, never received them). But, the end result was exactly what I wanted so I am happy overall.
I would recommend them, but I would stay on them about communication which I did not. At least that way you will be more comfortable with what you hope to receive.