You can find those lights online from US sellers, they just charge more because they buy from China and charge you a big markup. You may be able to find that at small electronic and hobby shops, and you'll pay even more because they ordered from China and now have to store them in a store with overhead.
they're lights, I wouldn't fret too much about RMA's.
As for how to convert to molex, get a spare molex plug, cut off the ends, cut off the end of the adapter, wire 12v to 12v and ground to ground. If you're not good with electronics or soldering, not the best idea then. lol.