I am purchasing BC racing coilovers for my G35x and I want to havea comfortable ride that is not too bouncy or stiff. The rep asked me which spring rate to go with 10/12 or 10/8...im not sure please help

10/8...it's stiff enough. Although 10/8 can perform on the track with the dampening set on hard, anything higher than 10/8 are for hardcore track people. Be aware that with most coilovers, your going to lose that OEM comfort.

Well it's really up to you. I have 10/8 and i want it more stiff lol

That's what she said.

I'm confused? Does BC make a coil over that fits the g35x (mine's a 2004). I cannot find aftermarket suspension parts that do.

They do now.