Checkout Airbyte and singer.io for data movement. They're tailored for moving offsite data local, but also have support for moving data between different database vendors. I'd recommend starting with Airbyte.

For transformations I'm a sucker for dbt-core, which executes transformations as SQL against your data warehouse vs. a separate process. This keeps everything simple and (generally) snappy. It uses the Python Jinja2 template library to compose SQL templates, and the process that parses templates to SQL also implicitly creates an execution DAG so you could have hundreds of transformations running in the exact order they need to.

There are also many commercial offerings (Fivetran, Dataform) that don't tick self-hosted, but could be easier to deploy if getting internal hardware support is an issue.

https://github.com/airbytehq/airbyte

https://airbyte.com/connectors

https://www.singer.io/#taps

https://github.com/dbt-labs/dbt-core