Hi Brett! Well, this two links should get you started on the 10 gallon conversion & build: http://www.frogforum.net/vivarium-te...struction.html and Frog Forum - Building Dart Frog Terrariums / Tropical Terrarium Construction.

However... even though Ranitomeya's are small; they do benefit from a larger taller enclosure like an 18x18x24 in. ExoTerra. Plant it well (include Bromeliads), vines and wood and you are set. R. ventrimaculata are more reclusive than R. imitators; so consider that while building their enclosure. Good luck !