My fear with a monitor would be it crying wolf. I'd end up sleeping through the beeps figuring it was another false alarm.

That's one of the reasons I didn't use a monitor, even though DD was on a monitor for apnea in the NICU for 3 weeks I was worried the monitor would fuel any mummy paranoia I had hehe.

you could always have him in your room, then you get to watch a sleeping baby and know they're ok instead of watching a little light. It's recommended to have them in your room for at least 6 months with the SIDS thing.