i don't think the v3xx allows you to specifiy which days of the week in advance that the alarms are to go off on. if i remember correctly, you can only set it for the next day.
the u600 allows what you want to do with the alarms. i don't know if it's available on AT&T though.
you have 5 separate alarms in total. for each of those separate alarms, you can set it it to go off on any days of the week (eg mon, tues, and wed. or maybe everyday of the week, etc) and repeat for each week. or you can set up an alarm to repeat once only.
for each of the 5 individual alarms, you can also set snooze to go off every 1, 3, 5, 7, or 10 mins, or no snooze at all. you can also repeat the snooze 1, 3, 5, or 10 times.
for each of the 5 individual alarms can either be a vibration, a melody, a vibration and a melody at the same time, or a vibration then a melody.
for each of the 5 individual alarms(i bet you're getting sick of me saying this ), there's an auto powerup so you can switch off your phone during the night and the phone will switch on automatically when the alarm goes off.
each individual alarms allows your own separate custom tones and volume control.