Benchmark

I have the following setup :
Apache 2 + mod_perl 2
Postgres 7.3.2

I need to is measure the perfomance of a ticketing system (written in perl)
which has web interface (html::mason, apache2) with Pg as a backend. Users
of the ticketing system can only connect to the backend via the web
interface
and they usually login to the system at the begining of the the day and
remain
connected untill they knock of. I have setup two test machines, one with Pg
and the other with Mysql. Both machine have the same data (sample).

I am looking for a benchmark utilty that the simulate a user session.
For example, a user login in, displaying a ticket and searching for tickets;
all these invlove a user connecting to the a url, like for search, a
user needs
to open "somehost.domain/path/to/search.html?with=arguments". The
utiltly needs
to simulate these actions.

The following tools currently have so far caught my attention:
Apache Jmeter
ab

I need suggestions for other utilities.