From your pictures, your repairs do not look too difficult and you can
obtain a kit, such as the West System, (http://www.westsystem.com/) at any
good marine supply dealer. The biggest problem you will have is the color
match. If your dealer does not have an exact gel coat color match, then you
will have to custom mix a color on your own, which is not quite as daunting
an you might think. Just take your time and and make samples to compare
until you find the right mix for the final coat.

One way to work on the keel, while it is on your trailer, would be to use a
hydraulic jack to raise the bow and then block it up.

It is doubtful that the keel guard product will prevent further damage if
you continue to approach the dock bow first, as it is designed for beaching
on sand or mud. Perhaps you might think about tossing a few fenders out on
the port side and letting your first mate off in this manner.