[TheThinkTank] Buying chain in bulk

Hey! I was referred to this site for buying (bike) chain in bulk. There are several measurements that I don't know what to select: http://www.mcmaster.com/#drive-chain/=1196wd Pitch: (i think this should be 1/2", but maybe it's 3/16) Roller width: ( I thought this should be 3/16ths) Roller diameter: (??)

This is what I came up with, I choose steel because it was 1/3 of the price of corrosive resistant steel and 5 times less than Stainless steel. Are these good prices: http://www.mcmaster.com/#drive-chain/=1199db maybe i need to go with the SS which would make this route not worth it Thanks! cris