Drilling a ten will be no prob, most large tank manufacturers only temper the bottom of 55 and up. I drilled some cheesy glass from lowes, and the pressure from the bulkhead and the plumbing pressing on it just a lil bit cracked it in about 3-5 days. so I would say three holes on a ten is a def. no. I made my own fuge from scraps of 1/4" that a local glass store just gave me. You might want to call a few, they throw so much glass away, and would not mind giving it to you, then just take it to lowes or home depot and have them cut it for free. you could potentially build the whole thing for just the cost of the silicone, just as I did.
good luck,
btw if you have a few 10's around why not try it, mock it up and test it.
-Odd