There are a lot of books, articles, and even websites on how to do this. I'd recommend using Progressive Epoxy Polymers
brand of epoxies over West, but would agree that the West Systems website has some really good resources for this. PEP has much better prices, is well recognized throughout the boat building community, and makes a low/no-blush epoxy, which is simpler to deal with than the West Systems stuff.
One thing that you could do that would result in a professional looking finish is to do the repair yourself and then hire a gelcoat person to coat the repaired area after you finish fairing and sanding it. This would be a compromise between paying someone to do the repair and doing the entire repair yourself.
For the fiberglass, I recommend Fiberglasssite.com.
As for the cold weather, you can buy an epoxy specially formulated for working in colder temps. The brand name is ColdCure epoxy, and it is a pretty decent epoxy as well. Personally, I'd wait until warmer weather though.
For safety gear, I'd highly recommend getting the full-face mask style respirator, like a 3M series 6000. These are far more protective and far more comfortable than the half mask ones. Don't even bother thinking of using the disposable ones....they're useless.
Any questions... just ask.
Hey Sailingdog! I've read many of your comments over the months.
If you dont mind, what are the best ways to learn how to do this right?