If you could find out what frame rate they cycle at--I can't remember--, then you could use any animating progame to test your texture, rather than trying it out in-game. Or, you could use the existing ones as a reference--put a bunch of different ones in a test map, and pay attentions to what looks close to what you want.
If you want it to look super smooth, you could use tons of env_renders and a custom texture of each "frame", to produce a something closer to video.
Slayerwraith hand a nice example for this, but he seems to have deleted it