Personally, I would opt for reefing the mainsail and/or installing a jib furler for single-handing during heavy winds. The C-14 sails pretty well with reduced sail area, and unlike adding large amounts of weight for stability, this option is easily reversible.
2016 Update on the Weighted centerboard.
The boat has been in water since '09 and there are no delamination or other issues with centerboard. There are a few barnacles on boat and cb.
I am moving to a Catalina 16.5K or C. Which means I will have to do another weighted centerboard if I do not get the keel. The 14.6 has become too small for 5 passengers. I will use copper core this time to prevent rust. You cannot cover Stainless unless you want it to weep and rust.
Its been a few yrs since i built that weighted keel core centerboard. Boat was bottom painted and left at a marina in salt water for two years w centerboard down. Only thing happen was one barnacle on drain plug. Zero problems. My daughter Used Micron CSC bottom paint.
Copper is way more expensive. You can double Galvanize steel if you are worried about it or you can put several coats of epoxy (not fiberglass) before lamination and use the same epoxy on fiberlass cloth laminates. Copy existing centerboard so it will fit in centerboard housing. Many keel boats used bare pig iron and just haul every 2 yrsand fair it w epoxy. If you aregoing to keep it on a trailer, There wiil be no reson for extra expense.
I did get a C165K. There are pix at the yahoo groups c165 site.