Hello,
I'm a computer scientist with a 5 year experience in Python. This project seems very interesting to me. There is only one problem: as far as I know Google doesn't provide a way to download the apk file to the PC (there are workarounds, but this is very complex and also there is a problem with paid apps).
Other things that make this a bit difficult are: google doesn't have a list of all the apps that exist in Google Play (there is no something like a alphabetical view of all apps), everything is grouped in categories, but this can fortunately be solved with small workarounds. One other thing is the number of apps on Google play (more than a million apps).
But, all of this that I have mentioned can be discussed and probably solved, If You are interested please contact me and we can discuss this.
UPDATE:
I just saw that You already have a python app that can download apk files, translating it to windows is probably not a problem, but I can't say anything before I see the code.