The problem with the places you list is that the dive resorts are pretty much self-contained and there is not much going on other than dive-related activities.
If you really only want to dive for a few days and do other activities for the remainder of the time, Bali is a good choice, despite the fact that it is right next door to you! There is wonderful diving up at Tulamben with honeymoon-worthy resorts and varied diving. It's also easy to set up a stay of a few days up at Ubud (also on Bali), and maybe some land-based tours of the high calderas of the volcanoes. Bali is quite different from Java, culturally, so you will still feel like you are in another country even though you will still be in Indon.
Alternatively, you could split your time between the sister resorts on Kapalai for diving and Sepilok on Borneo to visit the orang utan sanctuary. It sort of depends, I suppose, if you want all nature or a mix of nature and towns.