Agree with Spot, the viv isn't suitable for an older, fully grown individual . It should be much taller, longer and deeper as they feel more secure at a height and need space to move and turn around.
If you talk through what you were thinking of heat, UVB, diet and supplement wise then people can help make sure that its spot on. Substrate sounds ok, I would personally go for a heavier soil mix with a little bit of bark. This will hold humidity better.
How large is the water bowl? You prefarably want something they can bathe in easily, something like a large cat litter tray is good.