If low profile is important to you, I suggest you check these units.
http://www.wammiworld.com/kahler%20systems.html
Now I haven't seen or touched 7-string guitar equipped with this kind of tremolo, but it sure looks low profile
If you don't want to swap your blade kind of floyd on that guitar to rolling kahler, I suggest you get your current bridge measured and you can compare the dimensions to those given at warmoth's site. But as these are both Floyd licensed bridges, they might be even made in the same factory, so there is no reason to swap a bridge to a exactly the same one, unless your current one is damaged.