If you're buying the titan head, you wont need to buy all the ferrea valve train components as the head is ready built by titan.
You also cant fit the doluck tension set with the cusco cage.
You wont need the TRD flywheel with the OS Giken quad clutch as it comes in the kit.
Breather kit?
cooling plate
You'll need a lot more adding into that fuel system, lines, Fpr etc
EMS, i'd look at a syvecs s6 ecu for the money elsewhere put into the build.
Exhaust headers? downpipe?
Thats just a glance, but im sure it'll help you spend your time looking into it all
Best of luck in the future, i wanted a supra at your age too, and 8 years later i bought one, then 8.5years on, another