Surati Farsan Mart has the best to-go packaging out of any Indian (and even non-Indian) places I've gotten take out from. They put a lot of care into their presentation (which is why they are also slightly more expensive than the other snack places in Little India).
You know you could just make pani puri at home. It's super easy -- we do it for parties sometimes as an appetizer. You can buy the shells at any indian grocery store already prepackaged. MDH makes Pani seasoning, which you just mix with water and add your own chopped cilantro, etc. Boil and cube a potato, rinse a can of garbanzo beans, chop up some onion, and assemble. You can even buy your mint and tamarind chutney premade at the Indian store (the refrigerated and frozen ones are better than the bottled ones), or you can make your own very easily.
If you are a little adventurous, add some vodka or tequila to the pani.