If you are looking for a breakout board for the QSS-025-01-H-D-A socket from Samtec Inc. you will not find one with 50 pins at that pitch. We do carry several that should work with this connector they will just have some extra pins that you won’t use. Please review the datasheets and choose the one that best suits your application.
Adapter, Breakout Boards | Electronic Components Distributor DigiKey