Considering your sailing intentions, I'd get the lightest weight breathable foul weather jacket you can find. In warmer climates, if you get the serious offshore
gear type foulies, you'll be sweaty and uncomfortable. If you do sail where it's cold, you can add layers of fleece under a good "coastal" type jacket. I think it's important to get a breathable jacket and it's also nice to have the type with the rubbery inner sleeve that velcro's tightly around your wrist to keep from having water
run up your arm when you reach up for something. Try it on with the hood
up and see if you can adjust the fit of the hood so you can see OK.
As for foul weather pants, you probably won't wear them much anyway so they aren't too critical and there's no reason to spend much money
on them. You'll probably never wear them while ashore or doing much physical exertion so breathable isn't as important as it is for the jacket. In fact, since you'll be sitting down in them most of the time, and often sitting on a wet surface, complete impermeability is more important than breathability. Get a pair of thick fleece pants to wear under them and when you're down below you can take off the outer layer and still be decent and warm.
Tall boots so water doesn't run down into them when your pants ride up while you are seated.
A fleece hat that ties under your chin that you can wear instead of your hood when it's not raining or under your hood when it's really cold.
A pair of warm waterproof gloves. I've got a pair of the orange ones that fishermen use. They cost less than $10 a pair, are 100% waterproof, and have a wooly looking lining that does a pretty good job of keeping my fingers warm unless it's very cold out.
I wouldn't spend a lot of money
on them but if you have an old pair of ski goggles with clear lenses, bring those along in case you get in some really wind whipped conditions. It's hard to keep your eyes open if they're unprotected in even 30 knots of wind driven rain and spray, especially if it's salty.
Lots of thin layers are better than gear that is too thick and bulky much of the time.