I think I need to stay with the relay, as I'm using the NC terminal to sense the resistance of the ignitor to prove we're ready to fire. Maybe I could do it with two devices, one fed through an inverting buffer? What kind of timing issues could I expect with that setup? The sense circuit would have to be off before the power circuit fired, or I'd put 12V into an analog input pin, & probably through the current source for the sense circuit as well. Two identical FETs, one fed through an inverting buffer, one fed through two inverting buffers, one to match the first device, the second for a touch more delay? Or am I making it more complicated than it needs to be?