Looks very nice man.
But the only issue I see.
Is that water gel in water dish?
Would suggest to have it removed as water gel is not
Recommended for tarantulas.

For the first creation I then cut styrofoam in the shape I want and laid it out the way I want it. To get a feel.

I think you can sell them to a petstore for about R250 or so.
How much did you spend on the enclosure?

I think you could sell them to Petshops for somewhere around R200 to R300 which I think is reasonable and not too expensive either as they already have all the deco it needs. Just add Substrate and Spider.

Now is the very messy part. I smeared marine silicone on all of the back styrofoam, the platform and the one side of the glass. The I took dry palm peat; pressed and sticked the peat on the silicone.

I then let this get more or less dry over 24 hours. Then I started sticking the piece of wood and the platform in place. This I left for more than a week to dry and smells to be gone. The final step was decorating, by putting peat down and the water bowl and a little tree. Oh and don't forget the isopods.

Awesome!
What lid do you use for the tank?