Manuals come in three types:
a) Owner's - comes with new vehicle or from previous owner if he didnt lose
it!
b) Service (shop) manuals from manufacturer, in this case Nissan.  SOmetimes
similar info is produced by a third-party licensed by manufacurer or not
licenesed at all - someone just makes up a CD. book, etc. designed to
replicate manufactyuer's book.
c) Repair manuals from well known publisher's like Haynes, CHilton, these
sometimes lag in time, i.e. there's nothing for my new 2004 Sentra and all
they offer is pre-2000 Sentra's from Haynes

My solution was:
a) I have Owner's manual came with a new car, obiosuly; but also:
b) MULTIPLE service/shop manuals from Ebay, multiple because no one was
complete and a few were lying (generic "car repair" disk, nothign specific
on sentras) but they were so cheap I dont complain ($12-20).  So do this:

1. Search Ebay.  Sometimes supercheap ($15 or less) CD's are a hoax good for
any generic car but not your specific model and not deep, just basic crap
extracted from websites, books, etc.  However my manuals from Ebay were 100%
OK.
2. Search Haynes
3. Search Chilton
4. Check manufacturer's website, perhaps call.  In my case Nissan explicitly
SPELLED OUT HOW TO GET Service (shop) manual in the back of User's manual
(guide), i went there and found cost $100's, so not acceptable for a single
person like me (OK only for a large shop or someone rich), so got from Ebay
instead (not Nissan's official, but similar).
5. Check helminc.com
6. Search Web via Google, this is the last resort however this is how I did
find all about Chilton's, Haynes and helminc.com when I was a car moron
seeveral years ago, helminc still in business and I got owner's manuals from
them, buit no shop - shop was overpriced agagin.

Also I forgot to mention:
http://www.courtesyparts.com/nissan-manual/index.html
ALl about Nissan's manuals, parts, etc

Download one from here:
http://www.zeroyon.com/TheSite/techservice.html
Click on the appropriate model year once the page loads

Not sure if you can use the larger brake calipers from the newer 2003+
350Z as there may be a fitment issue. I haven't heard of anyone being
able to successfully swap over the 350Z calipers to a 240SX. You CAN
however use the brake calipers from an older model 300ZX - the 1990's
model year & above. Swapping over the 1990+ 300ZX calipers over to a
240SX has been successfully done by many.

Check the attached link for DETAILED information on what is needed & how
to do the swap.

http://importnut.net/300zxbrakeswap.htm

Hope this helps....

ID
95 240SX SE with 1990 300ZX 26mm front brake calipers installed

PS:
For additional information on your 240sx, you can go to any of the
following sites:
http://www.240sx.org/faq/index.html
http://www.amarok.org/modules.php?name=Sections&op=listarticles&secid=1
http://www.240sxforums.com/
http://www.zilvia.net/
http://forums.freshalloy.com/ubbthreads/ubbthreads.php

All are excellent sites to get detailed information from.