Induction kit for 3S-GE rev 3 Options

[ksporry]

It's possible that this has already been discussed, but its next to impossible to find the exact info here unless i spend a weekend searching manually through the posts, so if someone knows a post with teh answers to my questions, feel free to provide me with a link to those posts.

I would like to install an induction kit on my celica, which has a 3S-GE engine. I'm not too worried about the piping itself as that can obviously be tailored to my desires with, well, piping...
What I do wonder about is:
What diameter piping would I need for good airflow?
Any recommended routing?
Any filter size recommended? (I bought a cheap 10 GBP filter with heat shield from ebay. Doesn't look too big, and halfords sells the same size/look unit for about 30 GBP, so possibly the exact same unit...)
There is a small black box halfway the stock air ducting (between the filter box and the throttle body). What's in there and do I need it connected to the air ducting for the car to work correctly, or can i take it out completely?
Is there more associated to it? I.e. breather hoses to be fitted appropriately, temp sensors to be installed, tuning of ECU/fuel management.
At the moment I am not planning to replace the stock ECU and fuel management, because i want to mod the car step by step. Too many variables would make things far to complicated for troubleshooting.

Thx!