Relay Question?

[THE "10" SILVERADO]

I'm putting an ignition kill switch in my truck (along with another switch on the NSS) but I've got a question about which relay to use.

For the ignition I don't want to use a Bosch style because if the switch accidentally turns off while I'm driving it will still kill the coil power, what kind of relay can I put in that would cut power when the switch is off but after the car is started (ignition on) would stay on even if the switch turns off? So say if I hit a bump and the switch malfunctions it would stay running and only turn off when I killed the engine (killing the engine would work like a reset button or something). I'm sure there is something like that out there but I don't know what it would be called to get it.

Thanks
Michael