you may have to piece together these parts if your local subie dealer is not helpful. I have good luck with Advance Auto locally. It never ceases to amaze me when they have parts in stock, and they're always willing to order parts. Prices and convenience is hard to argue. For consumables like OIL, FILTERS, BRAKE FLUID, CARB CLEANER, PURPLE STUFF, etc for all my cars and the cars I work on, I end up being a "regular" in my local Advance and get good service, despite the fact that my "day job" is in Health Care.
Felpro's head gasket KIT was something they didn't stock but would order. I've needed water pumps, alternators etc. for various vehicles and they've had them IN stock so often it blows my mind! I also purchase hoses, belts, and brake lines there.. since I also do a lot of "hot rodding" of older cars and access to the parts is important. I sent my wife there with the family hauler when it's battery started to get weak, and even though the 2000 Passat is a "we don't install that one" battery - they still installed it for her..
Prob. depends on the employees at your local store, but one-stop shopping (even if you have to come back later to pick it up) has it's advantages.