You can look up the part numbers on either Denso or NGK's site and order from rockauto. I personally prefer NGK plugs. In either case you don't have to change them for a long time.
ngksparkplugs.com
And use the rockauto 5% off code if you buy there, scroll to the newest post:
Home | NGK Spark Plugs
NGK Spark Plugs (U.S.A.), Inc. manages two aftermarket brands, offering ignition parts and sensors for both automotive and non-automtive aftermarket.

And use the rockauto 5% off code if you buy there, scroll to the newest post:

Question for folks on here. What replacement spark plugs would folks recommend or are currently using to replace OEM?