How to upload large files within WP?

Hi Everyone, my users will need to upload large zip files from within wordpress. I would like to avoid making them use FTP to push these zips (50-100MB each) to my server. So my questions are:

1) what is the largest file size users can upload through wordpress?

2) is there a plugin or some other means to show the progress of the upload?

Any suggestions would be appreciated! Thanks!