Wing keels
Bud is right, as usual-you may actually be able to see the bottom of the keel from the dock if the water is clear, but it WILL look a lot like an inverted "T" at the bottom.
FYI, wing keels are generally pretty sluggish in lighter air-especially upwind, and are slower to accelerate (more wetted surface).
Given the 28+'s great light air performance, I would avoid the wing keel if I had a choice, and if possible stay with the standard keel. If your cruising grounds are REALLY shallow, I guess you have no choice but to go shoal draft-I would still choose the non-winged variety (strictly for performance reasons).
Good luck!