The reason that it is not long enough is because it is a
sub-snake, which is designed to link up with your main
snake for use on drums. this way you don't need to run multiple mic leads from the
riser to the stahe box. You use the
sub-snake instead.
Now I don't know what snakes are worth in the US but you may be better off buying either a second
hand (make sure you test it and get a warranty) or a standard format one (12x4 or similar).
Try the above links but you might find that it may prove more expensive to get one custom built when compared with one that would have more that you need but be a "standard" item.
The upside of this is if you do upgrade your
system to include more channels, you have a
snake that will be able to do this.