Hey eldorado, we have the same setup with the vent mounts.
Brian,
The link below from mountguys is what you want for the NavMat, which I hope you got from Amazon for a kick a$$ price. I got the NAvMat for my wife's Garmin and their mounts are long enough. I think TT had longer ones before for the older GO series.
Not sure if these are made by Tomtom but they should fit great.
http://www.mountguys.com/product_p/tto115.htm
You can see they also sell one with the NAvMat for like $30.
Use "
prior5" to get 5% off.
Here's a gooseneck one, but it may be a bit longer than you need.
http://www.mountguys.com/TomTom_One_Mount_p/tto120.htm