The cable you are trying to buy has a connector. Simpad doesn't have a connector on its board. You will need to solder either the whole cable or just a connector for existing cable. IMHO, it doesn't make much sense to buy a cable if there's no way to attach it, does it? And if you have to solder anyway, does it really make a difference whever solder the whole thing or just a part of it?
-albertr