Migration from M$ SQL

Hi All,

In our company we are planning for a migration from an
MS SQL/NT to PostgreSQL/Linux. The current database contains
mainly SQL standard data types(though a few user defined data types
may be there), is using Triggers and Stored procedures.
I have already seen the migration howtos available at the PostgreSQL
site. I have some questions to be cleared before we really start a
Pilot project for the planned migration:
1. How do we efficiently migrate data from MS to Pg? Is CSV good enough?
  The existing database size is around 25 GB.
2. Is there a systematic/regular mapping of SQL Scripts for MS to that
  for Pg? In other words, is it possible to come up with say, sed
  scripts, which would convert an MS Stored Procedure/Trigger to that
  in Pg?
Thanks in advance.
A very happy New Year to all :)
-Amitava Roy.