What mm chain size for long tincup necklaces?

[pinkjewel]

I'm thinking of making my own 45" tincup necklace. I used to make and sell lots of beaded jewelry a few years- so relatively simple to make. I'm having trouble finding affordable 14kt gold chain these days to make it, so wondered if anyone knew what mm size chain are the designers using- and what type of chain? Or even better has anyone here made one? If so- do the pearls need to be drilled wider to accomodate a larger gauge wire. I'd think anything thinner than 22g (at a minimum) would not hold up to frequent wear.