If you plan to go for a premium mailing, Mike himself gives some really good tips for software here (for merchants using Clickbank)
http://www.jvnotifypro.com/community...pic,424.0.html

These are easyclickmate and aweber.

For payment processing, you mentioned you use Joomla, which has some nice Clickbank plugins as well, but I also recommend the Clickbank module for Drupal here: http://drupal.org/project/clickbank_ipn


Good luck