Windlass
Go for the electric. If you don't anchor often the manual will still be a great improvement over muscle power. It will also be more reliable.I have a 336 and sail in Barnegat Bay too. My Lewmar electric windlass works great. It is installed on the anchor roller plate. The center divider was ground back a few inches to allow for the installation. The chain/rode drops into the bow, between the hull and the water tank, thru a PVC tube.Watch the power draw - mine draws close to 80 amps under full load . You may want to look at upgrading your batteries.I agree with Charles. The installation should not be difficult. The electric installation includes two pneumatic deck switches. The wire is a straight run from the starboard battery bank to the bow thru the very accessable starboard wire run behind the electric panel. Remove the panel and take a look. There should be no problem running the wire.The installation cost does seem high. Every job is based on time and material. $100 more for the windlass is a given, that takes care of the material (assuming they are including some means of control - up/down switch - contactor - circuit breaker). The labor difference should be installation of the circuit breaker, controller, and switch(s). This should take four hours max. (they know what they are doing right?). Check your labor rate, and ask questions.