Happy a happy birthday, Scuba!
As well as you know the island, I’d suggest you opt for one of the ‘sure thing’ places for a special evening. As Kim suggested, Le Cigale, many of the GC options or, closer to where you stay, LeMoulin Fou or possibly Sublime or make a sunset reservation for the new place everyone’s raving about near Orange Grove. Sorry, the name escapes me at the moment. Bamboo maybe?
Sounds like both Astra and Amore might or might not be the best choices for a special occasion.