Taking the plunge

[2000aleroff]

Okay so im just going to say screw my credit card and buy a starting turbo set-up. i know the basic things ill need:

Exhaust manifolds, turbo and housing, wastegate(if not on turbo), charge piping. and oil lines(dont know how much or what size though), and the down pipe of course.

is there anything else that i NEED? if i wanted to set everything up except for the down pipe(custom). would i need anything else?

And does the outlet on the turbo housing that attaches to the exhaust manifold change depending on the turbo? same with the down pipe... like if i were to get one turbo, could i simply upgrade by just swapping them? its not a big deal, just curious for future reference.

EDIT: bov and intercooler, haha forgot those 2