You will probably find it at either Rapid Electronics or RS Components, but you will need accurate measurements and the data sheets, lots of variations.
As above i would cut, solder and heat shrink if possible.
The Male part of that will almost certainly only be available in a PCB pin out configuration unless you are extremely lucky.
If its a standard generic part on the other end, then your best bet might be to pull a dead unit apart to salvage bits.
Alternately chop the cable and fit your own connector to both ends and make up an extension cable with the same connectors as you have just used, that way you can choose whether of not to add your extension cable in the middle.
Jst xh250 series... PM me and I'll send you one in the post next week, we use bucket loads of them at work. Have straight and right angled pcb mount receptacles too if required?