Sorry, and thanks headinclouds for putting me right - this is all in economy class.
They do not have a strong preference to use miles for either UGs or free flights, so it depends on which is the most generous option in the above situation.
How about the Platinum challenge? They would reach 10K in April and (presumably?) have OW benefits until the end of the year, so for their next two long-haul flights - and then could use their AA points for OW awards? Are there any major restrictions on earning miles on AA when flying CX? (which is what they will be doing to NZ).