Your Aquarium will work great!

I house all my frogs in Aquariums, it's not really about what you have but what you make out of it.

For darts, you can make a climbing background on three sides of the tank (using spray foam insulation sprayed onto the glass, then covered in silicone and coated with dry coco-fibre, makes it look like a rock wall), a water feature, a small misting system, plant some climbing/crawling plants, some bromeliad plants, and toy'll be ready for darts.

Also, if you plan on getting darts, the lid will have to allow for mimimal ventilation, as darts like high humidity.