You've got nothing in Terminal 8. I like the Sam Adams Brewhouse in Terminal 4 but you'd have to leave security in Terminal 8 and go through security in Terminal 4 to get there. I have no idea if the TSA allows those not leaving via Terminal 4 to go there to eat and drink.

Here's a list of the food/drink establishments at JFK by terminal and by pre/post security locale. http://www.panynj.gov/CommutingTrave...retail.html#t1