What kind of plugs to buy?

NGK #ZFR5N (stock number 3459). Extra-long electrodes move the spark away from the quenchout area for more consistent ignition across a wider range of fuel/air mixes, which gives a little better driveability and mileage.

Autolites are now Chinese-made garbage. Champions have always been cheap and nasty and are only getting cheaper and nastier. Hold an NGK next to its equivalent Champion and the quality difference is obvious unless you are legally blind or legally blonde.

Magnecor wires.