There's a 3 output grill ignition kit
available at Wal-Mart that's fairly popular. Powered by a single AA battery and fired with a push button.
I have one of them on my single tier to fire the HLT and BK 10" banjos. It's fairly easy to install. I mounted the controller to a welded hard point, drilled and tapped mounting holes directly into the cast iron burners to attach the spark thingies, and ran the wires through steel brake tubing I bent and welded to the frame more or less out of sight from the front. Works quite well...