Custom Drupal Theme needed

I have a html template (unfortunately it's not hosted anywhere right now) that is just basic html with the file extension being .php. The template has a Flash navigation menu and a Flash banner on top. I would like to get this template turned into a Drupal 6.x Theme. From what I understand, Drupal has it's own navigation system. I'd like to use Drupal's navigation, but I'd like it to look like the one on my template (if possible). I would like my flash banner to be incorporated into the theme too if possible. If it's not possible, then I need it to be somehow converted into an image that could be used in Drupal.