Indonesia forum

Hi guys
We're heading into West Kalimantan for about 4 weeks and are trying to make up some kind of itinerary which involves both some inland forest time as well as a bit of a spell by the water.
I'm having a bit of trouble finding any information in regards to beaches and islands though and was wondering if anyone could recommend somewhere nice, ideally with interesting snorkeling (I know East Kalimantan is much better for this, but we just don't have the time or funds to get across there as well!). The places we've come across are the karimata Islands, Pagatimun, Randayan Island or the beaches around Singkawang (Samudra or Pantai Pasir), but we haven't really been able to find much information on any of them. Has anyone been to any of these places and could give us a bit of an idea what they are like?
Our makeshift itinerary at the moment is looking at including walks in Gungung Palung and/or Bukit Baka-bukit Raya, Singkawang and then potentially Ketapang and the Karimata Islands or Pagatimun. Does this sound achievable in 4 weeks or are we being a bit too ambitious?
Any thoughts and comments would be greatly appreciated. And the sooner the better, we are on a bus from Kuching into kalimantan tomorrow. Once again we have left our run a little late in regards to planning...!
Cheers, Rowena