Here Any quality cable that maintains the signal integrity should work fine. We cannot recommend third-party products. However, here is a 6" audio extension cable that one of our customers recommendedreports works very well with our audio jack readers. We've had a few more customers tried it and confirmed it works try it with good results as well on their iPads. Hope it'll work for you too!
http://www.cablesonline.com/35mmsttmatfe.html
Specifications
Connectors
(1) 3.5-millimeter Stereo (TRRS) Male
(1) 3.5-millimeter Stereo (TRRS) Female
Gold plated
Length: 6 inches (0.5 foot)