I recommend 4-5 days at the Intercontinental at Jimbaran, it has one of the best beaches/pools/views/grounds and location, and the rates start around $160-200/night. In Ubud the Element is a very good brand new 4-star choice, at about $80-100/night with breakfast, but you can do more luxurious, if you want. I would suggest 3 days in Ubud and 5 days in the south.