Hello from Colorado!
I'm just getting serious about bioactive enclosures and will more than likely begin keeping dart frogs once my first enclosure is dialed in and has some time to grow. It's been fascinating reading through the build journals on Dendroboard and elsewhere online.
Currently I keep a 6-year-old jungle carpet python and a 6-year-old Hispaniolan boa; both were acquired as very young juveniles. Until a few years ago when I relocated to Colorado, I also raised a sulcata tortoise from hatchling to adulthood. (It was an incredibly tough decision adopting him away; I really miss keeping him. Happily I still get updates from his adoptive "family" and he's doing great!)
Even though adult sulcatas are generally kept dry and outdoors, I think that's still the most relevant experience to my new endeavor. (Snakes - at least mine - are so simple in comparison.) Sulcata hatchlings require significant humidity and daily observation/care, plus I created a pretty self-sustaining outdoor habitat for him as an adult. And I daresay, creating a healthy ecosystem in a suburban backyard may be harder than doing the same in a small terrarium...
I've got an 18"x18"x24" Exo Terra that I will be customizing. I've picked up some items from local shops, but am still waiting on some more to arrive from online vendors before I really get started. I anticipate a week or two of build time, then letting the cage "grow in" for 2-3 months before acquiring any frogs. I may wait even longer, since I lead a number of backpacking trips in the summer/early fall and wouldn't want new arrivals to be settling in during that time frame. (My wife will happily care for them, but I'd rather be around daily for new arrivals.)
I'm not really into breeding reptiles or amphibians, because despite my personal interest the supply/demand has never really seemed to add up in the best interests of existing animals. (Personal opinion.) I'm also only planning on keeping a single species, so more research is in order on that front. I'm building the enclosure with the tentative plan to keep a variant of thumbnail dart frog (or very similar); I've read they're considered a bit more "advanced" but the care sheets and care journals all seem well within my capabilities. Planning on a 4+ group, but that will depend on the final species decision.
If not a full build journal, I'll probably at least post some updates as the terrarium comes together. I look forward to continuing to participate on the forum.