Buying NEW red eyed tree frogs, where to buy.

Previously last year I had owned 2 red eyed tree frogs for some time they lived for about 8 months and were quite happy, I fed the 16 crickets every other day made sure they were moist and well misted and cleaned their tank every 2 weeks or so. But I ended up coming across what I thought might be a female as I had wanted to breed I bought her at petsmart and not knowing about quarantining your animals I added her straight in, about 2 months later all three died and each a day after the other. I am looking online for answers and to seek help, and where to buy, I have heard about Josh’s frogs, LLL Reptile and a few other places but I’m not sure if they are reliable, any answers would help, thank you.