I live in a colder climate and opt to use 10W40 in my car. It's also what the manual recommends. As far as the best spark plugs, the car comes with Beru plugs from the factory. I'm using Bosch in my car and they're great. There can be a lot of opinions when it comes to the "best" so sticking to or close to the OEM parts is always best.
Welcome to the forum! You should post some pictures of your car
