Check out Greenforcetactical.com they make one for the pps m2. Lots of local LEO use them for off duty.
http://www.greenforcetactical.com/custom-owb-holster/
Another option is http://pantherconcealment.com
You have to contact the owner via his web sight as he makes the holsters to order and he wants to actually wants to converse with the purchaser to find out the needs and wants and needs. He doesn't have the m2 listed but can make it.