Hi Chris,
I suggest that you have a look at this U.K. Government site before you buy a helmet:
http://sharp.direct.gov.uk/ I happen to use a Shoei XR-1100, but there are many other options.
A jacket made of heavy cowhide gives the best protection but it isn't practical in your climate. Like a previous poster, I like Vanson (I have a custom made leather jacket and trousers from them for my sport bike), but Vanson is a small company with very limited distribution. There are several companies that make quality textile jackets and pants whose gear should be readily available in Indonesia.
I agree that you should consider footwear that protects your ankles. Personally, I wear leather boots, with internal reinforcement, that come up to my calfs. These offer good protection while being comfortable enough to walk in. Mine are made by a company called Vendramini, but you are unlikely to find the brand in Indonesia. I'm sure that other companies must make something similar.
You might also consider gloves with protective padding. When I did my motorcycle course, at one point I was going extremely slowly, lost balance and went down
Of course, the first thing I did was put out my hand to break the fall. I was wearing a pair of Held Phantom gloves, which paid for themselves right then and there. A skinned palm with grit embedded in the wound is not my idea of fun.
I'm buying my first scooter today. In principal, I don't see what the difference is between an accident on a motorcycle and an accident on a scooter, but I have noticed that scooter riders, compared to motorcycle riders, tend to wear less, and lighter, gear. It remains to be seen whether I continue to adhere to the philosophy "all the gear all the time", or instead start taking more risk.