All of the Motorola phones Cingular currently carries can be set to vibrate on calls, incoming text messages, voicemail notifications, alarms, data calls, fax calls, etc (V180,V220,v400,V551,V3)

The vibration is strong enough for me, but my dad, who also has a motorola says the vibration isn't strong enough for him, so your best bet is get a working model in your hands to see if you think its strong enough.