@jnairn - "I am going to use Google Apps Sync because my company currently uses gmail and I want to sync gmail with Method??? Google apps sync will synchronize my gmail with Outlook, which will allow me to synchronize my email with Method???"
-Google Apps Sync allows Outlook users to use Outlook and Gmail. That then allows you to use the Method Outlook plug in. If you don't already use Outlook - this is going to be overkill, and you're better to wait for a couple weeks until you can use our gmail plugin.
In regards to your needs - everything you are looking for is there, plus more. Pretty sure you'll like it. It automatically detects the customer based on their email address, displays past activities, cases, opportunities and QuickBooks transactions. It also allows you to add activities, along with the email contents, sync attachments to Method documents, and create cases and opportunities - all directly inside gmail.