Optimizing complex queries

Hi all,

I've got to set up a program that automatically does searches for up to
10000 members (batched once a week at night), and then email the results of
those searches to them. The search query is rather complex, requiring up to
5 subqueries, close to 10 tables, many joins, and some full-text searches.
I've done the indexing, and has changed the run-time variables of
postmaster (i.e. sort-mem and number of buffers), and vacuumed the database
regularly. Yet, it's still taking a couple of hours on a PIII 850 server
with 512MB RAM.

I've read that writing the search as a stored procedure improves
performance. If so, how significant is it and what affects the efficiency
gains? Also, I think full-text indexing will help, but it's not supported
in postgres natively right?

Thanks in advance
Ryan