I've done some research on Spring Peepers and from what I gathered I thought they needed a lot of space and a taller tank. I'm not as sure about chorus frogs. If you put the 2 together you have to look at the risks of an enclosure like that. 2-3 peepers might be good in like a 29-40 Gallon because they need a lot of space like most tree frogs. The habitat temperature humidity and size must be equal or one species will become ill and wipe out your enclosure. A build like this will also cost a lot of money. I put around $4,000 in so far and it's been 2 years. If you are still stuck on these species try owning one of each for over a year and study them. Ask questions on here and research like crazy and you will have your answer. A mixed build requires much research and planning for success. I spent 2 years researching before I came to the conclusion on the animals some plants and the size of the tank. You should ask on the tree frogs thread there opinion of this because I am not as educated on local tree frogs. Thank you for your support, I want to help you and give you the advice that I had to find and learn from this experience. There is no cutting corners when lives are on the line. Thanks again I hope this helps!