Chatbot with database, what to use?

Question

Python

Good afternoon!
There is a task: to write a chat bot for Telegram (with possible subsequent integration into VK, Facebook)
Functionality: answering customer questions about available goods, placing orders.
For example, a chatbot communicates with a client, if the client asks a question about the availability of a certain product in the store, the bot accesses the database, checks if the product is in stock, and answers the client, who can then place an order.
There are a couple of questions on this topic:
1) Should I use Dialogflow or Wit.ai?
2) Link to the database - Python + SQLite?
I would appreciate any information on this topic!
Thank you!