So things are moving right along, and have the signup eBook download process working the way I'd like. Works fine with my testing anyway, hopefully when/if people actually sign up for the mailing list it'll continue to work.
I ended up using the Ink framework to develop the email template. The template looks good to me in both the Gmail Android app and Gmail web app using Chrome. That's all that really matters... I guess. I really like the Ink Inliner tool that Zurb provides. It really blows up the HTML, but seems to work great from my testing. Wish they released a command line version though. That reminds me that I should really look into finding another inliner, I know they're out there.
I also worked on setting up a HTML template in MailChimp, but ran into some problems getting things where I can actually add/edit text. I think I need to go back to their examples and figure out what kind of code blocks I need to add to make certain areas editable. I did this some to include the list preferenc links in the footer, but I need to test the variables and what not.
One more step along the path to actually marketing this monster full time... well part time anyway.