Just got off the phone with Joe from Zspeed. Just as everyone said, he was very helpful. Rather than replacing the slave cylinder, I went with Joe's recommendation and I will be replacing the entire system. I ordered a new OEM master slave cylinder and the stage 1 clutch and flywheel assembly which comes with the CMAK.
https://zspeed.com/product/nissan-oe...-g37-g35s-q60/
https://zspeed.com/product/zspeed-st...clutch-system/
Prices seems reasonable and the OEM clutch master cylinder is on sale. The reputation of Zspeed on this forum, their service, and quality of parts is definitely worth the price.
I'm ordering an axle back exhaust too, because why not. I don't plan on modding my car much as it is my DD, but I'm hoping these mods will make it better than it already it is. I already called a reputable shop near me and they will be ready. This is definitely adding up to be a lot, especially since I was not expecting any of this, but I'm looking forward to it!
Thanks to all of you who helped me.