If u have straight for es. 350cfm ventilation you will need bigger stuff, you have to know if u are creating an autonomous environment inside the box or you environment is conditioned from the room it’s placed in. I think the humidifier can fit in the box and is always better to use it with ro/distilled water to extend his life. I got along very well with the 4L taotronics humidifier. Obsviously you can set the disedered humidity from it and it works really well, no heat and a lot of humidity. Deumidifier it depends on where u live and your market, china is not the best option maybe some xiaomi stuff you can find it all around the world, but take a 18L /day with like 190/220w and a 5L reservoir for around 180€ and it will be the best choice. Obviosly with integrated controller with %humodity , power and maybe other settings, here i’m hoping to get one olimpia splendid acquaria 18p 170€ amazon prime, the deumidifier is 40€ Amazon prime and u can find it here in europe and i see some guys from america running it so i think is a worldwide china brand. Hope to be clear and useful ✌️🏽
Ps. I forgot, the deumidifier i will place it outside, inside it will be a little over, i will go if u want only inside for acquaria 12p , 12L day same function 130/150€ 190w 2.5L a little bit less of programming option like cloth drying and not the same efficiency but a great product