STM32F103C8T6 dev board with C and debugging
These Are everywhere on ebay/amazon and the like. The SWD interface is clearly labeled if you are questioning the PCB you posted. But for 3 dollars you might as well buy one, buzz it out then see if it fits your needs. Getting these running with the ST-Link Utility over the command-line and GCC is pretty simple. GDB is a different story, but there are plenty of canned IDE's you can use thet will work out of the box. Embitz is nice, as is the MCUonEclipse plugin. Hope this helps