If availability of channels is the only hitch in the minds of the consumers then i assure u that you do not have to worry. There is a Ruling from TRAI that all the channesl have to be provided to all the service providers irrespective of their tie ups. That means Star will be forced to give signals to Dish even though there is no tie up with dish tv. But the only deciding factor would be the price. SO my recommendation and advice is select ur service provider cleverly. If u watch a lot of Star channels go for Tata Sky, But if ur are a zee viewer on the majority go for a dish tv connection. This criteria has to be used assuming that the service given by both the companies is the same. From what i have heard, Tata Sky is more customer friendly rather than Dish TV.
So all the best dudes and make the right choice and do let us know about your choice and ur ownership, viewership experience.