I have always been an Android user and generally the cords have been trouble free but a quick look of Amazon found this iPhone cord
http://www.amazon.com/Certified-i-Blason%C2%AE-Lightning-Display-generation/dp/B00N0EFO36
Its got good reviews and it looks pretty nice too, and cheaper than an original.
For a very good contact enhancer/cleaner, look no further than Stabilant 22. I love this stuff! If its used in aerospace, it is certifiably good! I had actually read somewhere that this is used on the triggering contacts in things like missiles and other military ordinance . It has some pretty unique desireable properties but unfortunately its very expensive! But if you got a bottle and use it very sparingly like you should, it will last a long time and find more uses for it. You can dilute it with pure alcohol to stretch it out a little. It has fixed a lot of pesky electronics issues for me in the past, its worth its weight in gold!
http://www.amazon.com/Stabilant-5ml-Kit-Makes-30ml/dp/B001E50GQS