To step the voltage up to the extremes that you need to discharge a spark to some distance look up Tesla coils.

I think you will find that any coil or transformer that will do the job is going to be too large to be mobile with a single individual carrying it.

 

Paul

The ignition coil from an old car is fully capable to produce long sparks and is around the same size as an small Coca-Cola bottle.

 

Hey everyone, i may be a little late on this BUT, this is for anyone who sees it. You can make Pyrotex Gloves, of a fireproof glove (probobly find one made of nomex leather http://www.dupont.com/products-and-services/personal-protective-equipment/thermal-protective/brands/nomex.html) put a material on the fingertips (like sandpaper or a negitive type material) drip a little drop of oil (veary little) on them, and snap! spark gloves! Just like Roy Mustang from the popular anime series "Fullmetal Alchemist"http://en.wikipedia.org/wiki/Fullmetal_Alchemist In the series this man Roy, (who's specialty is fire, and commonly known as the flame alchemist) snaps and uses energy from his body to push air away from him and to the enimy mixed with gas, causing a explosion. Allthough it is not possible (as far as i know) to push gas with no trail left behind i hope the spark satisfy's you ^-^