Looking for a place in Suffolk County in August to have a baptism party

We are looking to go the cheapest route possible because we have a big family and of course the cheaper it is the more people we could invite. I was wondering what the minimum would be and the price pp. We would be willing to have the party day or night and a buffet. We would like to have an open bar and we are very interested in a place that has a nice outdoor area.
Thank you very much! You can FM me your responses if you would like with your available dates.
Amy