This is just a nitpick, but making the distinction properly may help you find what you are looking for - you want an INTERPRETER for the "live" translation. Written materials get translated, speech gets interpreted.
It's your decision, but I would not use someone untrained for the tasks you describe if you are relying on the interpretation/translation for professional purposes. In my job, I work with highly qualified translators all the time, and we still have to check their work carefully for mistakes. Translation and interpretation are professional skills - I'm sure there are exceptionally smart amateurs out there who could help you, but they would be unusual and you would be lucky to stumble upon one. If you don't speak Indonesian yourself, how are you going to know if someone is doing the job well, and how will you spot their mistakes? The old adage "you get what you pay for" is very likely to be true with respect to interpretation and translation.
Interpretation is understood to be extremely taxing and even really good people need a break fairly often. When my employer uses interpreters at workshops, we generally have two people who switch back and forth every hour or two.
Anyway, if you are able to consider using "real" translators and interpreters, you could start by contacting these folks:
PT. Laksana Tata Indonesia
(Business Advisory Indonesia)
They will not be as cheap as using an untrained college student, I'm sure (and I have definitely found mistakes in their written work, so nobody is perfect), but they are pretty reliable.
You could also contact Himpunan Penerjemah Indonesia, the association of Indonesian translators. They have levels of membership - if you need to watch your budget, maybe one of their "junior" members would be a good choice. I don't know if they offer interpreters as well as translators, but they probably do. Good luck!