The best way is to make a couple of custom functions. Start with HealAll, then ArmourAll or something. You need to call a loop round all the players ingame, setting their hp and armour respectively. Then, if it is under a command you just need to set 2 timers.
So something like
GameTextForAll("Healing in 3 seconds, boosting armour in 6.");
SetTimer("HealAll", 3000, 1);
SetTimer("AmourAll", 6000, 1);