Fermenting forms a large part of my work. Here is some of the kit I use.
Incubation setup for small-scale koji making (or anything else that requires maintaining a constant temperature)
ROKOO 5V USB Electric Cloth Heater Pad Heating Element — There are lots of USB heating mats, but I’ve found these ones to be reliable and inexpensive.
Places to buy koji spores from
http://gemcultures.com/ (probably the best when you’re starting)