D. tinctorius. Good choice, nice bold frogs, they should be very visible in the viv.
Up to 80 degrees. They can easily handle down to 65 at night. Humidity should remain high, but that's a delicate balance between spraying, water, air flow and mold. My starting dart tanks were quite interesting at first with trying to figure out how to do this.

The breeding thing will be troublesome for many, because it'll muddy things up, but I'm not looking to lecture or scold.