This page is helpfull: http://www.junkyardturbos.com/Rear-Mount-Turbo.php

I also found a few old forum debates where you can find more knowledable people than me discussing rear mounted systems, some saying it's a great setup, some saying it's a bad setup. A lot of crap is in these forums but there are a few good posts to read so you can get an idea of what the pros and cons are. Some threads:
http://forums.justcommodores.com.au/v6-development-modification/72209-sts-turbo-rear-mounted-turbo-under-car-what-have-you-heard.html
http://www.thirdgen.org/techboard/power-adder/238864-another-remote-mount-turbo.html
http://www.thirdgen.org/techboard/power-adder/289456-who-here-has-remote.html