Hi! I'm not sure if I get what you mean, but Nordic is not going to make dedicated programmers. We support J-Link only. You can use the nRF51 DK as a programmer however, but the "Debug out" connector itself does not have a supply line and is not able to power an external board. Instead you can hook up the other VDD pins on the nRF51 DK to your external board and supply it with 3 volts that way.
May this CMSIS-DAP jtag interest you ? It provides 3.3V and USB to UART bridge for the target device. Command line program to Flash Softdevice + Firmware + DFU all at once without requiring mergehex.
