Best Practices for Internet connection

Group -

What are the current best ways to connect an iSeries to the Internet?

My current options:

1.  Internet to stand-alone iSeries in a DMZ to production iSeries.
Stand-alone iSeries to do DDM to production iSeries for DB calls

2.  Internet to iSeries partition to production partition of the same
iSeries. Unsure how to do DB calls in this config

3.  Direct connection of production iSeries to Internet (with lots of
security)

Which of these do you favor and why?  Pros and cons of each?  Is there a
better way?

Thanks in advance,

Steve