I am currently using TomTom 7, which I downloaded from this site, with the TomTom 6.75 North America maps I bought from TomTom on their site. I had TomTom 6 before this, and it also worked fine on my Fuze. Sadly, TomTom has never released a newer version than 6 for the North America market (and may never do so), but TomTom 7 works great with the 6.75 maps. Just make sure if you do run TomTom 7 on your Fuze, you have the 6.75 maps or higher, as any lower editions won't work with TomTom 6.
I hope that helps, let me know if you need any more help!