Tank with no front vents
So I recently got a 36x18x18 vivarium and I looking to make it a nice Leucomela display tank. Its a front opening viv, but it doesnt have that front vent exo terras and zoo meds do. Previous owner used it for a bearded dragon, and I think its from the Petsmart "Thrive" brand desert terrarium kit (Im not really sure how to include images here but if you look up thrive desert kit from Petsmart its the same one).
How essential is the front vent? I plan on making a glass top with a strip vent at the front anyways. I got it for really cheap, and I could just put it back up on craigslist and get a 24x18x24 exo terra.
There is also only about 4" between the bottom of the doors and bottom of the tank, would that be enough space for the substrate and egg crate false bottom?
This is not my first viv, but it will be my first one for dart frogs. Any other input would be appreciated.