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No need to use Developer Edition. The unbranded builds of Release and Beta will have an update mechanism too.

They'll be en-US only, though, so if you want a non-English interface, you're out of luck.

If you want to use a non-English interface you would install the langpack for example https://ftp.mozilla.org/pub/firefox/releases/44.0/win32/xpi/ you would need to navigate the ftp to match your particular install.