How to go to git from svn without checkout

Hello. I've been falling more and more in love with git and I want to move our biggest project biggest it is my biggest pain over to git to make our lives easier. The problem is our project is about 50 gigs (A lot of media files involved). Also, we got developers all over the world that are running on slow connections. Some took a week to get the project up and running in the first place. Luckily, they are only isolated instances. What I'm wondering is can I have all of them turn their projects into git repositories locally and have all of them sync with a master repository once they are done. The actual project is only about 500 megs and the changes are probably only a few K since they keep their projects up to date, so that's more acceptable, but I don't want them to bring down all those media files again and I doubt they will be willing to do it. Is this possible, and how would I do it?

thanks