You can find Rhino II packages that come with the mount. They are simple helmet shrouds, but they work well enough. The Rhino II is way better than the original Rhino as it has more adjust-ability to it. It is an excellent entry lever mount and works great with the PVS-7.
I would go with a plastic bump helmet before a ballistic helmet unless you need the protection. Use the extra money to get an IR laser or illumination. The ballistic helmets are no fun to wear when you are out playing around or hunting. I got a ballistic helmet mainly as I like collecting military gear, but I don't use it for the most part. So unless you have a real need for it, consider a plastic bump helmet first or even a non-helmet head mount (like a Crye Nightcap which I have on order). I even use my bump helmet when riding my mountain bike at night as it offers crash protection that ballistic helmets don't.