We received your logs thanks .
The url to LinkId=150675 is the link to the manifest of files you can install , which I assume did work since you were able select products .
The URL for Web Gallery is LinkId=145755 , you can find this in the log .. however the infromation is the same as the error you posted and not telling us why here.
DownloadManager Error: 0 : Error while downloading file 'http://go.microsoft.com/ however fwlink/?LinkId=145755'. Exception: System.Exception: Url 'http://downloads.sourceforge.net/gallery/gallery-2.3-iis.zip' returned HTTP status code: 301
The problem is that the server is sending a 301 permanment redirect instead of the expected 302.. Web Platform installer is not expecting this response and generating the error. While if you download this directly IE is handling the redirect behind the scenes.
To install this once its downloaded we use the Web Deployment tool to perform this. I will test and see if we can run this manually to work around this .