My wife and I would like to go Honeymoon either at Bintan or Batam, like to help me decide?

My wife and I would like to go to Bintan or Batam for a short honeymoon, since we want something near Singapore.

Any suggestion, tips and price ranges, and how much we should prepare? I think 3D2N will do or 3D4N?

Is it okay if we just book by ourselves in the resorts and not go to travel agents? Any thoughts?

Thanks!