How can I get these photon 2s without pins?
It is not possible.
If you want a SMD compatible device you should directly use the P2 module instead of the Photon 2. You will need to add your own power supply, connectors, buttons, and RGB LED.
The Photon 2 is not available as a castellated module because there are components on the bottom.
What's it cost to do all that? More than a Photon 2?