got mine done at a glass shop for $25
2 holes shouldn't be a problem. gutting the "no guarantee" was difficult, but it's only the cost of a new piece of glass if they bugger up. in a 37gal that's probably not much..
when I got mine drilled, I worked it out what it would be if they broke it and I had to replace the glass, and it was still cheaper than buying a hang-on overflow..so I did it. It never broke, and I'm very happy!
