Buying the cruise: Shop Discover has 5% cashback on various cruise lines (all the bookings are done through the Cruise & Vacation Desk travel agency, at no markup). From experience, the 5% is only good on the fare, not the tax/port fees, so realistically it's more like 2.5% cashback.

If they are ready to book now, consider this.
I got a flyer from Chase:

Call 1-866-951-6592 to book a cruise from April 2-June 30, 2012, and earn 5% cash back.

When I called, they confirmed that any Chase UR card I use will earn an additional 4% in URs. So I used a Sapphire Preferred for a total of 6% URs.
I don't think there's any deals for redeeming miles and points on the cruise.

See picture:


One caveat. It might actually cost more to book the cruise now than to wait. Cruise prices often dip when there's a lot of excess capacity within 60 days of the sail date.

Buying the flight:
I'm flying from RIC to YVR for 12.5k United MP. I'm flying from ANC back to RIC for 12.5k United MP. Revenue flights would be ~$330 one way. I checked AA, but they did not have Mileage SAAver flights. United seems to have the most availability of 12.5k one way's. So I'm getting about 2.6cpm of redemption value on a set of North America economy plane tickets... not too shabby methinks