Got it in the mail today! Took a bit of set-up, but after consulting the guides here, my setup looks more or less like the one in
this article in particular, with the heating lamp on the left side of his tank, then uvb next to it, then there's the cool side. I mounted it inside the tank, fyi, not on top of it. Haven't gotten around to getting a bew thermoter yet, will do as soon as I find the time.
EDIT: sent prematurely, sorry
Either way, he seems happy w it and it does seem like he's livelier now! Seems like he really needed it. We're going to the vet tomorrow again, but it seems like he's doing better! And the poop (vet fed him yesterday) looked good today too