I guess I would ask how much and what kind of wine you are looking to store. And do you have any alternatives for the wine.
For wood shelves you can order 1/4" x 4 x 36 planks from Woodcraft.com. Just cut these to length for shelves, two pieces per shelf is fine and gives you room between the pieces for air circulation.
Fans- I have two Oust fans in each of my Vino's and honestly I dont think they do a whole lot. I dont really pay much attention to the difference in Rh from top to bottom, I trust the beads to do their thing and my cigars smoke just fine from wherever I pull them. I like the idea of using computer fans mounted in a box or on a piece of wood, but that involves running wires through the vent and setting up a timer.
Beads-Two pounds is more than adequate
No problem putting the humi in the cooler, but unless you have a dual zone cooler storing both might be problematic. Most wines like it cooler that the 65-66 degree range where you would store your smokes. If I had a case of Sterling Oak Cab I would pull the smokes and put them in a cooler after freezing, then use the wine cooler as it was meant.
