Particles: Research for Smoke clouds

We've started particles in programming class and we will now be creating a particle for our racing levels. So I was trying to think about what kind of particle to do and was coming up blank, so I watched a few tutorial videos for UDK and Unreal 4 and deciding to do a smoke related particle. Next I had to figure out what would make my particle unique, so I did a little searching over the internet and found these:

I was thinking of applying these rings of smoke into my level, and I thought it'd be cool to have the houses in it to be emitting a smoke particle every so often. So I started with learning how to do a smoke particle in Unreal using this tutorial (four parts): https://www.youtube.com/watch?v=1GmlIfTsRaQ

And thus I made this:

Next is figuring out how to delay the smoke rings, and of course making the ring part. I was thinking of using a mesh emitter for the ring and have a texture over it. And create something similar to this:

But with a more "cloudy" effect.

I will probably also have it as a dark grey texture.