Go with Willy's units, they are a perfect fit and look great too!
I know that the manual brake and clutch fit directly off the 350Z but I don't know if the automatic ones do, go with Willy's and be safe!
I've been driving with the complete Willy set for like 5 days now, and let me tell you, they are great! After installation, I noticed an immediate increase in HP and I find myself staring at my feet like some wallflower at a High School dance! Seriously, get 'em, they're quality, and Willy's a good guy that'll see you through the install and questions you may have! (PS: I have the 5 sp set)