I want to edit it a bit and add a few different servers here and there (depending on what I need). Does anyone know how to find the actuall url of maps that the server fetches for downloads?
When a Q3 server sends you the files you need, it's sending you them natively via your UDP connection to the server. The server doesn't provide an HTTP (web) interface to obtain those files.
I don't know if it's possible to obtain a list of pak files which a server is using, sadly I suspect that it is not possible.