Gin and Tonic RTD

HI,

Im looking to make a Gin and tonic RTD. I understand the amount of gin, water, sugar and quinine I will need to add. What levels and substances do I need to add as-well? IE preservatives/citric acid? Any help would be appreciated. We’re making 1000l Batches.

Per litre I have a working of this
887ml RO Water
49g Sugar
64ml 78% Gin
0.08g Quinine

Thanks,