I think most should be safe to drill except the 55gs. I've heard all of those are made with tempered glass to sustain the pressure given their narrow/tall dimensions.
You should be able to find out if any glass is tempered by looking at it with polarized sunglasses. If you see the patterns (like car windshield) it means it's tempered. Also look for perfect finishing on the edges. if it's less than perfect, it's probably not tempered.
I just drilles a Aqueon 40 Breeder last week. Here's some info from their website:
Aqueon Glass Aquariums Tempered vs. Non Tempered: Due to glass availability, Central Aquatics may temporarily substitute regular or non-tempered glass panels with tempered glass panels. Anytime a glass substitution is made, a sticker will be adhered to the aquarium bottom as a precaution to the end user.