I've recently purchased some Granite Devices servo drivers and I need to interface them to my breakout board and encoders. There is a 2x7 and 2x8 header on the GD's that I need to connect to. What I'd like is a small PCB-mounted female header with outgoing screw terminals if possible. Since these headers are on the outer edges of the driver's PCB they can plug right in without using cables. I've scoured the internet and I've come up with more hits for small block Chevys than anything applicable.
You will probably not find a source for pre-made header adapters as you describe them. You could have some custom made, but the cost would be pretty high.
One suggestion though...
Find some reasonable small PCB mount screw terminal strips and some ribbon cable headers that will fit your 14 and 16 pin arrays. Use very short pieces of ribbon cable and solder the individual wires to the terminal strips. Pack everything together with a glob of epoxy putty (the kind that you cut and kneed to mix) and shape it and form it as you need it.