Hi Nicola,
It depends on how big your database is going to be and what sort of information you need to store.
If it is going to be quite small and not require sophisticated search queries, then it will probably be easier to simply load and save JSON data to the internal sdcard. If it requires multiple tables and you need to do SQL 'join' type queries, the SQLite might be a better choice.
What is your database going to be like?