yeah stick with the NGK CR8EH-9's.... the 9EH-9's are pointless unless all she see's is WOT and redline all day long.
and ALWAYS run NGK's ..... denso's are crap... you should see the huge difference in wear between the "same" denso and NGK plugs in the same motor.... for example in a toyota 3.4L v6.... toyota has a weird contract with the two plug manufactures and all the 3.4L v6's in their previous generation of trucks came with one side (3 cylinders) of ngk plugs, and one side of densos... at 100k miles the gap on the NGK's and wear looks very minimal compared to a new NGK.... the denso's on the other hand typically will have a gap twice as large as stock and a center electrode super worn down.
EDIT - btw. i JUST did my plugs yesterday (used NGK's 8EH's of course) ... couple of tips.... REMOVE the coils completely... mark which goes where (both coil to frame orientation, as well as coil wire to plug orientation, and harness to coil orientation).... all the plugs come out with relative ease, you just have to get smart with number 3.... this is where a foot long or so piece of tube that fits over the top of the ceramic of the plug comes into play.... Break the plug loose, and loosen it till its on the last copule of threads or so... then stick the tube down in the hole and grab onto the top. twist the tube n pull the plug out... for putting the #3 back in, do just the opposite... put the plug ceramic in the tube snugly, and gently feed her down in the hole... the plug will find the actual threaded hole then start spinning the tube while guiding it straight... she will grab and walla plug in the hole... tighten her up properly then do the other 3.