Building My First Crabitat

[Urchin]

I am new to hermit crabs, and I am setting up my first crabitat. I am really excited about this, and any and advice about how to better set up my crabitat, or recommendations about the products I am considering using, would be very welcome. I will of course , be setting up all the food and water necessities, but for this post I am mainly focused on the crabitat itself.

I am planning to use an old 40gal hexagon. This particular hexagon is much wider than the usual hexagon.
I am planning to set it up with a substrate that is a 5 to 1 mixture of play sand and ecoearth, that is about 8 inches deep. I also plan to have;
• a "Zoo Med Reptile Fogger Terrarium Humidifier", (because I live in a very arid climate)
•"Ultratherm"Under Tank Heater or "Zoo Med ReptiTherm® Under Tank Heater"
(It can get cold at night where I live, but it it rarely truly cold)
•"Zoo Med HygroTherm Humidity and Temperature Controller"
•"Zoo Med MoonLite Reptile Bulb: Nocturnal Reptile Lighting"
inside of a
"Zoo Med Deep Dome Lamp Fixtures: Reptile Light Fixtures & Hoods"

I do not have my heart set on any of these products, so if anyone has some better suggestions,I would love to hear them.

I am planing to have a driftwood climbing structure, so that the hermit crabs can reach a potential second level. I am also planing on having several hides.
I think I want to attach cork board to the back three panels using foam adhesive tape. My plan is to attach the cork board a couple of inches above the substrate, so that it will not get as wet, and to use a piece of driftwood to bridge the gap between the cork board and the substrate. I am hoping that using the cork board will allow for me to create a better second level, and give the hermit crabs a much more 3 dimensional crabitat.
One question I had was, if I put up the cork board, and I have an 8 inch sand bed, will that prevent that heater from working?

I'm so excited to be getting ready to build my crabitat! I would really appreciate any help that anyone has to offer:)

[Breeezy]

If you want to save some money on the humidifier, I highly recommend the Crane brand tear-drop shaped humidifier. I got a small piece of clear hose that fits right into the little top nozzle, taped the removeable nozzle down (didn't want it to get bumped off on accident), and put the hose right into my tank. It makes a cool fog effect, just like the store bought reptile ones.