i buy my RO water from walmart, here they have it in the same section as the distilled. they also have it at Bruno's but i doubt you have a Bruno's in NY, i think it is a southern chain.
i have heard of some people haveing the water truck deliver those big 5-10 gallon jugs to their house. the company was called alhambra where i used to live, but it is the jugs for those water coolers in office buildings.