If this is the only trip you can plan on going for the next couple of years, then yes, go to Anguilla and enjoy it, knowing that like people are saying, it costs a pretty penny. If you can book another trip in the next year or two, try staying overnight in Anguilla to start the trip for a day or two, then moving over to SXM for the balance of the trip. Your group would likely have fun at The Red Piano in SXM, but it is a distance away from the Divi. I am partial to Monday nights there, but note that it is smoky in that place. If we want a place to sit, we might get there around 8, but the action starts after 9. Very attentive cocktail waitresses there. Our groups have shared many a bottle of champagne there. I am sure you will enjoy your birthday, whatever you choose.