That is a very wide area.
Just do a search on “sky lantern” at Amazon, there are a ton of hits.
http://www.amazon.com/Outsunny-50-pk-Paper-Chinese-Lanterns/dp/B0092KI68C
My neighbor had some. The fuel is like the firestarters for charcoal like you use with BGE cookers.
I used to make hydrogen and fill ballons with it, carefully tie on a greased cotton string, light it and release. It was fairly low key.
Well I then graduated when a bottle of helium showed up at work. I would fill one balloon with helium, and then another with acetylene. the 2 balloons were then tethered to each other, then the bottom acetylene balloon got the greased string treatment.
It was a balancing act getting the “fuse” just right but after some trial and error I got it.
Releasing these at night you could see the flame at the end of the string as is wigwagged back and forth... timing these from the flash to the arrival of the explosion, I was able to determine they were about 2 to 3 miles away, and judging from the angle above the horizon about 2500’ elevation.
That wasn’t good enough though.
The final product used helium for lift in a large garbage bag... and the explosive charge was a stoiciometric mixture of acetylene and oxygen... which yielded a very VERY violent and very loud explosion.
This was pre 9/11... if I did this now-a-days... I would be the last one 0bama would set free from Gitmo.