The 36H will probably work. Unless , of course, you have the funds to have a custom wall unit build $$$
Sadly ...you be a slave to keeping it clean. I can just imagine what the glass will look like after a day or 2 two?

But......... good habits regarding cleaning / maintenance etc will be the trick ---here !

That's a lot of frog poop !

You might seriously think about a simple wet paper towel substrate / at least - 2 lg feeding bowls / and 3 or 4 soaking dishes
This will enable you to keep things really clean. All of this will have to be changed out every-other day.

Also adding soil substrate in this tank will take up a lot of needed ' living' space.
Keep in mind - there is 5" below the doors of the 24 and 36H exos.
So........... 36 x 18x 5 is a lot of space to give up when adding substrate--- just a thought---my 2 cents.

That --area's volume --- is approximately 3,240.0 cubic inches = about 14 U.S. gallons

Sharing ----I use 2--- 36H exos for tree frogs one 36 x 36 H and one 24 x 36H --- neither have substrate.
The screen tops will have to be modified to keep the humidity set.
And.... they are difficult to keep warm- even a bigger consideration for Whites.

All things to think about....not impossible ...keep us posted