Well, you have three conditions - beach, luxury and April. All three - won’t happen. And a lot depends on your definition of ‘luxury’. If you exclude beach from your condition, there are plenty of options.

As far as Bali, or pretty much of any beach in this region goes, I would suggest to keep your expectations low to avoid disappointment. Trash piling up on beaches is a serious problem and certainly it is problem for Bali. You can have there like 200m stretch of beach clean and manicured, but walk 5 min and you will start seeing piles of trash.

If you are willing to beach let go, than there could be plenty of options.