in reply to Oracle Character Sets
At my job we're using almost exactly that combination: Perl 5.8.0, DBI 1.32, DBD::Oracle 1.12, and some Oracle databases with the WE8ISO8859P1 character set. So I don't think you will see any problems with either of these character sets.
But since you're changing the character set anyway, is there a reason you're not going with utf-8?
In Section
Seekers of Perl Wisdom