With that combo I'd start with 3924 on the street, or 3923 on the strip and use plug reading methods to determine the final choice for each use. I try to use the strip choice all the time, and only change-up one hotter if they foul too easily on the street. Don't confuse plug reading for fuel and spark tuning with plug reading for heat range.
Brand is a big deal to some and not to others. I run what's given or specified, and otherwise ones with decent quality but reasonable price so I can change sets repeatedly during tuning, like Autolite, NGK, Denso, etc. It's common to go through several sets in full tuning regimes. Each company has it's own heat range and numbering system that are unrelated to each other. Be careful if changing brands to test the 'crossover' listing, as they are often far off from each other. Re-test in that case to verify and avoid issues. Depending on your use (NA street, blown methanol drag, etc), sexy expensive plugs are a waste (like double-platinum 100,000-mile plugs) as are most hard-core racing plugs unless you have specific reason to run them.