Plugs, the NGK standard or iridium tipped plugs in heat range 9 are a good choice. Do not run the iridium tips if you are getting detonation! The tips will eventually come off and the engine does not like these hard little tips going through it.
The Brisk silver core plugs (available from Nology dealers) allow a bit better output from the stock coils and plug wires when pushed hard. These work even better with a set of Magnacore wires. We sell all of the above.
The best octane boosters I have tested are ACES, and NOS brands.
In the UK, there is an even better one, but I have yet to find a way to ship it stateside... but still trying.
I hope this helps.