I'd agree. While I haven't made anything other than beer, but, 1oz by weight per gallon is my rule of thumb for bottling... I assume it'd be similar for a hard cider/lemonade.
Keg #1: - Hefeweizen
Keg #2: - Mild Ale
Keg #3: - CO2
On Deck: Black IPA - Imperial Stout - IPA or Double IPA - Mocktoberfest