Custom wiki login page

I'm trying to customize the wiki/blog login process to behave differently. In particular, I'd like, rather than have a login AFTER selecting a link to a user space to which authorized access is required, to instead build a custom login page that contains the usual login window (which is presumably the javascript snippet we see there, referring to various .js libraries in /usr/share/collaboration/javascript/) BEFORE any groups or users are listed. A plain white page, or one containing our logo and formatted according to our custom theme .css would do.

I'd then like to send the authenticated user to a second page, dynamically generated or displayed, that discloses only the Group wikis and User blogs to which they have access. So that rather than seeing a list of all our current contacts and clients (bad look) they get their own custom choices and can proceed from there.

My hunch is that the first thing should be possible just with Javascript, the second may need some custom XSLT or even Python to serve the required HTML. So I'm prepared to go that deep - but obviously, a static page of html in the right place, and some way of manipulating the visible lists via Javascript, would be simpler.

Anyone tried this? I'd be keen to know how you approached it...