Good list of mods so far but I think you're next mod should be one of great importance. Especially since you'll be wanting to 'turn up the boost.' An upgraded clutch will be necessary if you want to hold onto all that new power you'll be getting. You've gotten off to a good start with the mods you've listed.
I'm assuming you'll still be using the stock turbos, so boosting beyond 16 psi is not recommended. To go beyond that you'll have to upgrade your turbos.
The stock fuel pump will be sufficient until you go with much larger turbos and much larger hp. You should consider upgrading the ignition with HKS's twin ignition amplifier.
Since you're changing the diff's ratio, are you also incorporating a different limited slip?
Your mods will work out great. I think you should also invest in some better brakes as well. Going fast is great, but won't do you much good if you can't stop.

 

There's my old age catching up to me.
How about this for an alternative to a clutch then?
http://www.specialtyz.com/transmission.htm
This should help you and your automatic transmission out quite nicely.
Z1motorsports.com also has lightened one-piece driveshafts that you might be interested in.

 

You'll want a popcharger to make that stage three complete. 2nd on ignition and brakes. And start saving up for upgraded turbos...that's where the real power's at since your motor will be ready for it with upgraded injectors and a fmic. you're a lucky one to be able to make a list of stuff to buy for your Z and gladly add on to it....if only I had extra money........