273 Commando Spark Plug Wire Options?

Be cautious with 8mm wires- the Commando valve cover wire insulators are sized for 7mm wires, and will require drilling them out to fit 8mm or larger wires; and they can break quite easily. Just so you know.
Whatever you end up getting, test the wires prior to installation. I've been getting a lot of sets with bad connections lately. Better yet, get bulk cable and make your own.
Yes, do not use 8mm. Wires.