dynamic typing questions

[Jason Tesser]

I work for at a college where I am one of 2 full-time
developers and we are looking to program a new
software package fro the campus. This is a huge
project as it will include everything from
registration to
business office.  We are considering useing Java or
Python.  I for one don't like Java because I feel the
GUI is clunky.  I also think that we could produce
quality programs faster in Python.  

The other programmer here is very concerned about
dynamic typing though in Python.  He feels like this
would be too much of a hinderance on us and too easy
for us to make a mistake and not catch it until
runtime making debugging harder.  

OK what are your guys thoughts here?  How have you all
overcome the lack of static typing?  Is Python a 
bad decision here?   By the way we will be using
Postgres in the back if that matters to anyone.