I've looked into this before... There are two different ways in which a wine-cooler keeps its temperature and it is important if you want to convert to a cold cure / humidor thingamajig. One results in more consistent RH is the end result i believe... bit faded on memory, if i can findn the link i'll paste it here.
Thermoelectric wine cooler is what you want.. not a compressor-based cooling element. Definitely need some 2-way humidity packs, but go with Boveda... After using both brands (integra for last 2 years), i can tell you without a doubt teh boveda packs work better. The integra packs are a much, much slower release or uptake of moisture... they are fine only if the container is left sealed for long periods of time and do virtually nothing for a smoke-jar that is opened daily. Get the boveda... they do caost a bit more.. They have a 320gram pack, or 67g per 1/2 to 1 lbs... Not sure what weight you are butting in there, but humidity colelcts at bottom, so i'd put one at top and bottom. If the bottom one gets heavier you can switch them around. Well-dispersed will more tightly control humidity throughout volume.
I don't know your currency in those pictures, but I'd make sure the "Cannitrol" brand is more expensive before modifying any wine cooler, since the work is done for you and has a few extra gimmicks of convenienec, i bet. Also, some wine coolers don't cover the entire best range of temperatures for curing. Make sure it covers up to 64-66F, i'd say. They are EXTREMELY overpriced, lol, but you never know until you look.