Well, Lion Air do seem to be expanding.
But I would look into the following points that arouse my suspicious nature:
1. Indonesian DGAC had some restrictions on foreigners (non-Indo nationals) working as F/O within Indonesian airlines, specially those with no or few hours on type.
2. Salaries in Indonesia tend to be fairly low, unless you are particularly experienced in a particular area of work. So I would query the amount that you mention.
3. Seems rather expensive for an FAA 737 type rating. I should have thought max 12,000 USD would have been more realistic. Could you not do a 737NG rating elsewhere (as generally all FAA training is recognised by the Indonesian DGAC)?
4. I dont see any details regarding recruitment on the Lion Air website.
I enjoyed my time in Indonesia, and in general it is a pretty good place to work. Sorry I dont have more specific info on Lion Air.
Finally, the old addage comes to mind that if no-one paid for jobs (via type ratings) then probably no-one would have to. Personally speaking, I would feel insulted if, after paying in the region of 100,000 USD for a JAA (F)ATPL course, I was then asked by an airline to part with another 24,000 USD for a job!
Good luck, and keep us posted how you get on with Lion Air.