I have all the accessories for the product including their switches, but never used them so I cannot comment on how they are holding up except that mine look brand new after 3 years . The LEDs are HUGE and the Piezo speakers are also bigger than optimal. I just measured the pin spacing and it looks like 1.5mm spacing between pins.
Here is an image of one I found on-line and this is from a CPU fan, so you may already have one you can use. If you need anymore measurement let me know, but I would start by looking for a computer CPU or case fan with this same style 3 pin connector to see if it fits into the header on the board. Maybe your local computer clone store.