Build an Openstreetmap website with Python for me to host

I am looking for a developer to build an Openstreetmap website with Python / Flask for me to host. I want to be able to use it as a starting point for me to further develop. It doesn't need to be very user friendly, as I will be the main user - to select map areas and coordinates for another project.

I am looking for something similar to this:
https://boundingbox.klokantech.com/
but I need to be able to
- lock the aspect ratio of the selection box
- show more than the bounding box coordinates i.e. the center coordinates and total dimensions of the selected area.

Optional: ability to select layers to display in the map, for example OSM tags like this:

{'building':True, 'landuse':['residential','commercial']}

Ideal Skills and Experience:
- Strong knowledge of Python and Flask framework
- Experience in working with Openstreetmap
- Ability to customize map layers
- Strong understanding of web development and hosting
- Ability to integrate additional features and functionalities as needed.