PostgreSQL 8.4 - permissions for newly created tables?

I have to setup a new infrastructure with postgre software. I would like to use user access patterns from mysql if possible. For every application:

1) one user for reads: grant select on db.* to 'reader'@'ip space' ...;

2) one user for reads/writes: grant update,insert,select,delete on db.* to 'writer'@'ip space' ...;

3) every user comes from a defined IP address space.

I would like to give one postgre db to one application.

1) and 2) - Is it really necessary to give permissions for newly created tables for such users every time a table is created (I am using 8.4, not 9.X)?

3) I think that kind of functionality is best to accomplish with pg_hba.conf?

I also would like to give ALL database for newly created application database rights for a lead programmer, so then he/she could give permissions for newly created objects to reader/writer application roles.

Is it the best way? Any hints?

Best regards,

Rafal Radecki.