I prefer the NGK V-power plugs myself. I started with a stock plug for a standard engine and the car didnt like that to much. I ended up going 1 heat range hotter, car so far is happy.
I think its going to be a trial and error thing for you.
I use the V-Power plugs myself and they are as good as any other NGK in my oppinion.
The sales pitch for V power is that the spark is out in the open a little bit more because the V forces the spark to go to one side or the other of the ground leg.
Probably 99% snake oil and 1% difference it makes anyway, but what the heck.
At least I don't fall for thinking that the V is going to add 10hp, or 5, or even 1.
:D
It's pretty much just a sales gimmick. (Still good plugs though)