800HP ... dyno proven... those are not street cars. The key test of a "street car" is to take it into traffic or to go grocery shopping. The I6s in supra and GTR will make 600HP on stock internals, just uprate the turbo. But a 13B-REW... I dont think so. 450HP is believable number without crazy mods but reliability compromised.
Your injectors are not enough because you will need to uprate your fuel pump as well.
The most important is to get ported so you have enough exhaust gas to spin huge arse turbo.
Also, turbos dont "blow up". Engines do.
Finally, this whole mo' p0wah! thing can get quite excessive. The final analysis is that xxxx HP is big a bragging point but not much else. There are very few useful applications for 500+ HP machines unless you wanted to enter into Group N racing. However, if you are set on hitting that 800 number:
1. 13B-REW - port a huge monster port, I think Ah Choy can get you to a j-port and then get a spare engine... for when this thing blows up - and it WILL blow up eventually
2. Radiator - get the biggest triple pass you can find, and then get another one...
3. Oil coolers - you will need 3 sets - two for the engine in a sequential setup, one for the turbo
4. Turbocharger - a HKS T51R KAI ... but why stop at 800HP? Get a T51R SPL for 1000HP!
5. External water pump - you will disable the stock pump,
6. External Oil pump - you will disable the stock pump, Bosch is recommended.
7. High pressure fuel pump - you will replace the stock pump, and add at least 2 more lines from the tank to feed the thirst, I recommend Bosch or Nippondenso and you will need a pair
8. Extended high pressure fuel rail - your new pump feeds to this, reduces the pulses in the standard setup, you may need to custom make this one
8. EMC - get a Motech or other engine management, remember to get a good O2 sensor, and a 3 Bar MAP sensor
9. Fuel Injectors - 1680cc primaries, 1200 secondaries
10. 3mm seals... for safety...
....
if you are not yet bankrupt from buying all of the above, we can continue... with a water or methanol injection kit, the rest of the drive line and stopping the damn thing. To be honest, I dont know what sort of clutch to put in this sort of setup but just make sure you get one rated for whatever HP you want.
... I just did a quick and dirty calculation, you can buy another FD with all the mods listed above.