Can benefits to the Alternate Payee be made over either the Participant's lifetime or the Alternate Payee's lifetime? In other words, is it acceptable to provide an option to the Alternate Payee where the payments cease upon the Participant's death?

Think about it this way. Aren't you describing an annuity for the life of another? Does the plan offer that form of distribution? Not any plan I have seen.

But you can get to a similar result if the participant starts a joint and 50% survivior annuity with the alternate payee (presumably former spouse) as the contingent annuitant. If the QDRO provides, and the plan allows, the annuity payments during the participant's life can be split in two between the participant and AP. If the participant dies, the AP continues to get the same amount, not from the divided payment, but as the survivor. If the AP dies first, the full payment is thereafter restored to the particpant. When the partipant dies, all payments stop.

Or vice versa.