I agonized over this decision when I migrated my application to PostgreSQL. I know Tony Caduto likes Delphi and he can give some good reasons for this (are you out there, Tony?). There has also been a good article recently about Ruby on Rails. For my purposes, I wanted to maximize cross-platform compatibility and decided on Java. I was advised (correctly, I think) to opt for SWT rather than standard Java Swing and ended up with Eclipse. I must say that Eclipse has not been particularly easy to learn - the documentation is quite uneven and the mail lists aren't nearly as helpful as with the PostgreSQL community. Also, Eclipse is changing so quickly that books have a hard time keeping up. Nevertheless, it is powerful and I've found it rewarding. To make things easier for others, I uploaded a basic Eclipse front end (without editors, views, and reports) to pgFoundry (Komo PostgreSQL Client).
On the second question, I also like to have the database do as much of the work as possible.
Michael Schmidt