I've found that a small sealed 6V battery is plenty for my ignitor equipped engines, one about the size of a 2" cube will be adequate, Minimag who sell the LT coils also do these batteries but easily available elsewhere.
As for plug wire you can get the look of braided spark plug wire just by using braided cable intended for wiring old cars though that may be a bit heavy depending on what scale your engine is, looks OK on my 1/2 and 1/3rd scale engines.