As with most of the posts my vote is for a mask (that fits). AND a snorkel, do you really want to chew on something that 100 other people used? EEEWWWWWWWWWWW......... Even though most dive operators provide full-foot fins a dive bootie would be a good investment. They can be reasonable in price, and even if not used in a open heel fins they will keep you from sliding all over the dive boat. The are good for walking a rocky beach for snorkeling too. Fins can be pricey and it may take a while for you to settle on what you want.
If you have a reason to get into "The City" check out Leisure Pro with a wide range of products and prices you can find a price point between cost and performance and there is plenty to choose from. I have never been to the Brick and Mortar but I have purchased online.
Here is my favorite shop and local to me http://www.northeastscubasupply.com/store/. They also run a great six-pack charter out of Brielle N.J. if you find yourself ever crazy enough to dive local. They are about a 15 minute ride off the Pa. Turnpike Norristown exit.
GOOD LUCK
Wish I was going with you.