Some Napa stores carry Royal Purple, but not all. And the ones that do tend to carry the motor oil or the lube or whatever, but not all of it. I just said screw it and went with Mobil 1 again, motor and tranny. Diffs are next.

As for oil filters, I use the Fram X2 Extended Guard (XG3593A). It's one of the best out there and is actually the ONLY Fram filter I'd use (the rest kinda suck and use cardboard instead of metal in the caps). I would have gone with a Napa filter (theirs are made by Wix) but I read up on this stuff and chose the Fram X2. Definitely avoid the new Fram one they have that disperses Teflon into your engine. And the K&N oil filter is more pricey than a lot of them with better filtering than it has.

By the way, I had a very reputable shop do my tranny flush and the whole process used 21 quarts. A lot of it stays in the converter and a drain and fill won't get that. Apparently some flushes don't either.