If you're looking for a light to mount under your OFM using our Action Camera Adaptor here's a few we have come across which work well with our adaptor. 

Garmin Varia UT is a great compact light. 

Bontrager has various adaptors to suit their ION range of lights  

Lezyne also have adaptors to suit their range of lights 

Shred Lights make a Light Pack that is designed to attach to our adaptor

If you find you don't have enough room under the OFM to get the desired angle you can add a straight extensions arm to give you more adjustment. 

This is just a few examples. There are lots of others options out there which are only a Google search away.