I'd try out Denso K20HR-U11.
It is listed as a stock replacement on their site, but it is equivalent to a Bosch heat range 7 and NGK heat range 6 which is one level colder than stock. It has all the same specs as stock; 14mm thread, 26.5mm reach, etc.
I couldn't find a Bosch or NGK plug that was a regular copper/nickel plug with single ground electrode and met all the same specs. So I'd give this a shot.
Here's their decoder info: