It supports any GH60 PCB.
I know the GK61 series will bolt right into this.
I personally have a GK61XS which is both hotswap and Bluetooth. However, the GK61s are considered to be sub-prime boards.
I know the Polarity Works BT60 and the nice!60 PCBs are both coming out soon and will support hotswap and Bluetooth.
I don't know of any non-Bluetooth PCBs, because I only use wireless, but there are a bunch of GH60 PCBs that are hotswap I'm sure.