Tablet & Android phone sync, using the phone's internet access?

I have a Samsung Epic 4G and would be interested in purchasing the Samsung Galaxy Tab (or another comparable one that would work) if there is a connection available between the two as well as if I could use my phone to bluetooth connect to the Tablet to create the internet connection when not in WiFi range. My hope there is that it would eliminate the need for the data package on the Tab separate from the Epic 4G and that it would allow me to sync data between the two with ease, such as documents, files, music, pictures, video, etc.

I am a Phys Ed teacher as well as a Driving Instructor and would like to use this while outdoors in the fields and being able to access e-mails on a tablet while at the same time being able to update grades and many other things that would be beneficial to my class on-the-go. For being a Behind-The-Wheel instructor, being able to show a video on a Tab on how to perform a Maneuver while in the car would be a really great use for the Tab, as well as not having to carry a paper clipboard, but being able to create and edit documents that are saved on such sites as GoogleDocs, etc.

Any help on this?