I've been rolling my own custom servo extensions for years and have been very happy with the results.
Get the better crimper along with the wire and connectors and you'll never look back.
Do some of your own diligent research as to which is the best size and type wire for you as well as connectors and you'll be making your own like a pro.
It really is that simple.
This has been my supplier since the beginning.
Hansen Hobbies - Products