I'm sorry for your loss! It's hard to make a mistake that ultimately leads to the death of your frog. You are not alone though, even experienced keepers cannot always predict what their frogs will get into. That's why, if you read through threads, you'll see something about a frog escaping a new viv and etc. Do not beat yourself up. Remember though, if you get a new frog, keep it in quarantine for a minimum of 30 days so that you're sure of his/her health before introducing it to your other baby. Make sure they are similar sizes also before putting them together.

I was doing some googling, and it looks as if PA has the same laws as WI and you will not be able to purchase a grey tree frog at the show. You may want to look into this better, I just did a quick search. Your best bet may be finding another newly morphed grey tree frog or tad.