For 150k and some flexibility, you could do 2 saver awards in Business to Hawaii, the Caribbean, or Central America.

Hawaii is a bit cliche I suppose, but the sunrise at Haleakala in Maui is quite a sight. St. John is very lush and laid back and is a nice place for quiet time.

The real expert in this area is my stepbrother, who has proposed to three different women in Fiji. Maybe the third one will take.

Best of luck to you.