Spark plug rating for Honda Accord 1999?

My current spark plugs might be causing a little knocking so I want to change them. They're also old.

I have 170k miles on my car

I know what brand spark plugs my car accepts but the heat ratings are 5 and 8.

What ones should I get?!

E3 plugs are good & cheap http://www.carid.com/1999-honda-accord-spark-plugs/e3-spark-plugs-12193266.html
If you want something better take Pulstar http://www.carid.com/1999-honda-accord-spark-plugs/pulstar-with-plasmacore-inconel-electrode-pulse-plug-21711819.html

NGK, Denso, or Bosch are ok as long as it is designed/rated for that car.
You knocking is caused by the valves out of sync/timing and hitting the pistons, bad fuel can also cause knocking and misfires.

Put NGK spark plugs in it and get the heat range that came from the factory. Heat ranges being off may cause a misfire but a knock is questionable. When's the last time you did a valve adjustment? Every mechanic knows Honda has a common problem with the valves getting tight and they need adjusting every 60,000 miles. At 170,000 miles you may have a little piston slap, does it go away when you rev the motor?