Here's the US supplier I used for the second set I HAD to have right away, the first 2 sets were from China / Hong Kong and were too long ago for Ebay to have retained the transaction
http://cgi.ebay.com/ebaymotors/1xPVC...Q5fAccessories
(This is a link to one of their current auctions)
As to holding up, they have been on for over a year with no failure, the cart is always in the tall grass, mud, snow, water, etc (in fact, one time I soaked the cart good enough to stall it out late at night and the LED's just kept on glowing, hahaha)