Ok....
For the engine...
If you choose to go SR20DET, then you want the GTi-R engine. It is the better one. The GTi-R has stronger rods, and cool things like individual throttle body's. I would say this would be the way to go for mega HP.
If you choose the SR20VET, that is cool as well. (BTW...it comes in the X-trail, not the Terrano). You can build this engine up just as easily, but if you are going for all out insane power, then screw the VVL. It's a waste of money if it's not going to be street driven. (personal opinion)
As for suspension, check out
http://www.truechoice.com. Call them up and tell them you are interested in the Phase IV suspension for the B13. It's like $4000 or something obscene, but it's the best there is.
For brakes, if you haven't found gigantic rotors and calipers yet, call up Mossy Nissan (
http://www.mossyperformance.com). Talk to Greg Vogel, and ask if they still have the SMC Big a** Brake Kit. They may not carry them anymore, as SMC is no longer in existance. If that is the case, call up Nissan Motorsports, and get ahold of Steve Christianson. He is the one who owned SMC (hence the initials). He now works for Nissan Motorsports, and will be able to tell you the best solution. He is the Brake God. The kit did cost about $3000 for front and back, not sure what it will be now.
Hope this helps!