I caught a few Nassau Dead shows in my time (I saw Kiss there for my first real concert ever back in the mid-seventies), but LI has always been a PITA to get to from Joisey (from anywhere actually, LOL!). I much prefer Madison Square Garden. Back in the day you could get toasted right on the train which takes you to and fro no muss, no fuss and no driving. The Beacon is cool...I've seen a lot of shows there, but never the Dead.
I wouldn't feel too bad about missing Joisey: where you live may not have the Dead Head vibe of the NE Corridor, but you get those cool outdoor shows, it's cleaner and there are less people. PLUS you got Harleys, Domestic Brews, Cheese, and Brats! Not too shabby.
Alright, Joisey's got Budweiser (NOT my fave)...I smell the sickening cooking of the barley/hops mash almost every day as they're right next to EWR airport where I work.