I would go for the Caravan even with Susi Air.
At least you have some "guaranteed" hours instead of some hypothetical flights...
Indonesia is not such a bad country and apparently Susi is full of expats. I met a couple of them in past few weeks and they seem quite happy.
They fly the Caravan with 2 pilots but with the local environement it is not a bad idea. You will get good experience with nasty weather and operating in remote & also on big airports.
The money for local standards seems quite good even for the "FO" on the caravan. Life in Indonesia seems quite acceptable at least in the big cities. Well there are some political tensions but for time being that does not affect the foreigners.
If you have a better oportunity later, 2500$ is really not a big deal...