Yeah, the plug chops were a bit confusing to me but once you finally see the ring, you'll know. You'll need a place to do one for sure...
Again, you may not need to upjet with just the pipe.. Adding the filter for sure.
Any of the links so far will have those roller kits. I had ordered a cheap one myself and it's held up o far.
That way you can spend the good money for the best rollers and they won't fall apart on you like some cheap ones out there.
That's a good thing that your pipe doen't have the "cone" in it.
Have you ever checked the wheel ratio?... (mark the wheel and clutch bell at a point, rotate the tire untill they line up again. Count the clutch turns vs the one wheel turn). I do believe some of the zx's had different gear ratios.
I do believe you're just going to have to "bite the bullet" and "jump in with both feet". Get the filter installed, check plug, get a roller kit, Stiffer springs in the cvt... 1000 main....1500 clutch springs if not 2000. Then maybe we can get you to checking the squish band.