Well it's very doable with that comp. Not sure what dps you need exactly, but 150k in gear that is generally available ain't nothing to crazy nowadays (keep in mind that there is a 30% dmg buff in icc). If your son is doing 300k, your 4 dps 150k each and the tank 100k (single target) you have 1m raid ddps, which should be plenty to kill it.