My advice from working in similar project is to use native speakers, do not ever trust language converters online. Usually what we do is hire consultants to work in house, have tested a few companies yet usually better results come via internal work.
I have designed a few large scale SEO strategies, really you need to work with the client to see what they require.
A good strategy is:
1. If you have the money use seperate tlds for each area (also important to use language specific domains), use seprate content for each area made by local copy writers. This strategy will work best for ranking on a global stage. Ive tested it numerous times
2. If you are strapped for cash use sub folders on the domain for locations, benefit of this is that you can transfer the link juice to the sub folders.
3. I would not advise clients to use sub domains for a international marketing camapgin, I have seen first hand the damage they can make, they do not even rank in global serps, they do not pass link juice as Google treats them as a seprate domain.