Please note that I don't know anything about the firm.
If you're in southeastern Bucks, Cherry Hill isn't too bad of a commute (given that most commutes are unpleasant in the Phila area). The western parts of central and southern Jersey are pretty accessible from eastern Bucks.
I wouldn't recommend living in or immediately around New Hope. It's a fun place to visit, but the tourist traffic is a mess during the warm seasons. Don't live in Jersey either; the property and income taxes are significantly higher than in PA.
Best idea yet: Live in Bucks county, but stay within reach of Trenton, NJ as you can commute via New Jersey transit to NYC fairly cheaply. When I visit NYC, I take the train from Hamilton, NJ...it's only about an hour away.
If you have to trade at an office, best to go to NYC.
rec: try www.benchmarqtrading.com - ask for Nick....tell him "Mark" sent you. They've got a terrific set-up and competitive rates.