I hate being a newbie (however, if you want to know how to build a 1000+hp Mustang, ask me)

Anyhow, I plan to change the oil in my X5 this weekend and I see that I need a BMW Oil Filter Element kit and new crush washers. Are these available at Napa / AutoZone or only at BMW?

Also, I live in the Texas heat...is 5W-30 safe or should I go with 15W-30?