Correct and best spark plug for 2014

I'd like to buy some new plugs so when I pull them to check valves in the fall, I can replace them then (since I'll be taking them out).
I'll have about 10K miles then. I asked AF1 about what to buy and they said there were two used that year. One early in year (2014) and one later. My bought my bike in April of 2014 and it came directly from the US Whse (in Dallas area?) to MPH Cycles in Houston.
They are saying that early bikes had NGK PMR8B ($19 US) and the later ones had NGK CR8EKB ($12.50 US).
Has anyone gone through this? I can't understand why these bikes would have different plugs.
I could pull them and look but I thought I'd save the buggering up of the plug wires etc until I really needed to.
Are there better plugs to buy for this bike than the NGK? MPH originally told me I could keep the originals in the for 18K and not the 6K the manual says.
Many thanks.

Expensive PMR8B ones use Platinum, cheaper CR8EKB ones use Nickel. I think it was discussed here before that cheaper ones are just as good. I've had PMR8B running for last 16k miles & don't plan to change them anytime soon - just pull them and check them and refit at services....probably a million opinions on how long they last under normal service but I suspect north of 20k miles easily

...and cheaper ones might last longer as they are multi-ground

Moto International recomment NGK CR8EIX Platinum plugs with NGK SB05F spark plug caps. The plugs are single electrode, which I prefer.

CR8EIX (4218) are Iridium...best material for spark plugs and available at any car part store in the US, plus they are not expensive.
So put those on and don't look back. ;-)
Been using these plugs since 2010 when I got my first GRiSO. I'm golden.