For a reasonably stock motor, no real need for the 8mm wires. They were popular back when high-output ignitions were deemed "needed". But as time progressed, even the OEMs stopped using them. Before I went back to OEM wires on my '70 Monaco, I tried some Taylor wires, but they still had the carbon-core-style conductor, so the real difference in them and stock was the coating on the conductor, plus the distinctive plug boots. Some might differ, but I like the BWD (formerly Borg-Warner Cool Wire) magnetic suppression wires for the particular application (already terminated). Less total resistance than the carbon core wires and very long lasting.
Plugs are another area which can have many opinions. I used to religiously use Champion plugs in the stock heat range. Then discovered that equivalent Motorcraft plugs lasted longer and ran just as well. Then I discovered the NGK V-Power plugs, which worked a bit better due to their gap design. Then went to the newer NGK Iridiums. Gap in the .040" range, for good measure.
IF accessibility to the plugs is an issue, but you don't drive the car very much, then what you need is a basic spark plug of the correct heat range. BUT if you plan on driving the car a lot or it's a pain to get to the plugs, the much more durable Iridiums can be the best choice (at least 100K mile durability).
The factory spec gap is .035", but the old Mopar Perf Race Manual advised that with a sufficient powerful ignition system, there is no need for more than .060" gap. So to me, going to .040" gap range is a little bit better than stock. The wider gap allows more of the mixture to be exposed to the spark. Which is related to a key design component of the NGK V-Power plugs.
Personally, I like things which have a stock OEM look, but are better than what the car came with. Just me. If you like the colors of the aftermarket wires, your judgment call.
Enjoy!
CBODY67