read this entire website and scroll down to the steps and read up on what it takes to boost this car.
My Turbo Installation
Ross' Probe GT Performance Page
this should answer your question.
and it takes about 1500-3000 to build and install a turbo kit.
im already a lil over 2500. and i pretty much got everything. im only waiting to install my clutch and flywheel next week or two and its boost time. let me know if it helps.
where are you located?
ps. save the body kit for next time around and do 'all' your maintenence first. i mean all of it. calipers,rotors,pads,water pump, timing belt, pully set, probably a new flywheel or get yours resurfaced, more than likely you have over 100k. plugs, and suspension. what ever you can think of do it before you boost.
otherwise youll spend all this money and things start to fall apart all over thte place.
it took me over a year to build my turbo kit and finish my maintenence list. ill be done with clutch/flywhl.
good luck on your goal