I need to have a bunch of different webform e-mail templates with different text - how do I create those with code in Drupal 7?
Webform emails are themeable using
.tpl.php files just as nodes, views etc. There is a THEMING.txt document that ships with Webform that explains exactly how to do what you are after, although the bit you're looking for is near the top:
If you want to edit the e-mail sent by only one particular webform, rename the file "webform-mail-[node id here].tpl.php", replacing [node id here] with the node ID of the webform.
There's also this handbook page on Drupal.org: Customising the emails sent by webform