Hello @gnd and welcome to the forum!
As you guessed it right, the best possible solution for your task would be rclone mount
.
We have a community member working on a php library, which progress you can find here:
https://github.com/storj-thirdparty/uplink-php or more specific in this pull request:
Let us know, if there is anything else we can do to help you get this working!