physics - 8:50 pm on Mar 28, 2008 (gmt 0)
This can be done with a relatively simple perl script and cron job, but you'd have to hire someone to write that custom.
Another thing to consider is more tightly integrating this monitoring into the software running on the machine. I.e. if resources hit a certain point not only send an email but do things like throw up a 'We are experiencing a heavy load, please try your query again in a few minutes' notice, killing database queries that have been open for 'too long', and then logging and possibly emailing the situation might be even more effective.