A week ago I installed the ebay one sent from Greece. The new rubber is definately stronger than the original one. I had the front end appart for painting anyways so installation was fast.
There is a video on youtube about installing the gaiter. When installing the upper plastic ring I found it easier to place the ring on the gaiter first and then slide the whole thing on top of the balljoint.
I was also a bit worried when sending money to Greece but that guy still delivers!