The perfect spot in on main street between Casey's and the Plaza Ice Cream. However, it's also everyone else's perfect spot, so it'll be crowded.
If you can buy a preferred spot it would be very expensive. Getting it as part of a package as mentioned above, might be the best method, if you can afford it.
I think that some of the "Dreams" that are granted each day are for VIP seating/space at the nighttime fireworks shows, so maybe you'd be lucky to get a "Dream".