Consider Malaysia. Stunning beaches, excellent diving (diving is really cheap too), spa resorts, delicious food and friendly people. And to top it all off it's really affordable. I have been to both Malaysia and Maldives and would rate Malaysia much higher. Maldives is very nice but I found it get's a bit boring and since you are stranded on a minute island everything is very expensive and you don't have choice of restaurants etc.

Langkawi has some really nice spa resorts at affordable prices and has fantastic reefs for diving.
SPG has the westin (10k a night), sheraton (7k a night) and the andaman (10k a night). So you could book a fair few nights with your SPG points (average paid night = $190ish).

Oneworld flys there from HKG so you could do a fairly easy trans-pacific with CX and then connect to KL. You have enough miles for their world renowned First class too. HKG would be a great stopover for a few days too for some shopping and sightseeing.

So overall:

Flights:
RDU-JFK(AA F)-HKG(CX F)-KUL(CX J)
270k AA miles for both of you.
If you want a stopover in HKG then you can add 30k AA and 40k BA for the extra leg to KUL.

KUL-LGK with MH
Y = $67 (each)
J = $316 (each)

Hotel:
e.g Westin Langkawi (10k a night or 4k + $60)
Assuming you are going for 2 weeks. Book 12 nights with points and cash for 48k + $720


You are left with lots and lots of spending money and it will go very far in Malaysia. You will be having daily diving sessions and spa treatments

Just a suggestion ^