Ubuntu + RoR + Firebird OR Ubuntu + RoR + PostgreSQL ?

Dear friends, I am starting to build a system for an university using RoR. I would like to use Firebird because I worked with it for a long time and I love it! In this new project I will use a lot of stored procedures, data referential integrity and so on. But when I looked for the Firebird adapter for Ruby and the activerecord for Firebird adapter, it seems to have so few support and so few users, that I am afraid about its future. This is one of the most important e-mails I've sent on my life....! If I have to start using Postgre the time is now. But with a great pain on my heart for the Firebird. Could someone give me a good advice? Thank you very much!