Model Display Products helps out with your template needs with their new steamcog rings.
From the update:
Model Display Products and Firestorm Games have teamed up to design a set of Steam Cogs for use with a variety of Sci-fi, fantasy and steampunk game systems as area effect templates. Set 1 comprises of:
3 x 3″ Steam Cogs
2 x 4″ Steam Cogs
1 x 5″ Steam Cog
These Steam Cogs are supplied in a durable polyurethane resin and come unpainted so you can paint them to your army/faction theme!
Also available is a second set consisting of 7 x 3″ Steam Cogs