I would go to Hotscripts.com and do a search for gaming or ladder and you will find some php scripts that do what you are looking for. Of Course as is they would use thier own database which would mean two seperate logins. But maybe if you made a request over at Portedmods maybe someone would be nice enough to alter the code to point to the nuke database (if you are unable to do so yourself)

to make it seemless in nuke you could use iframes or better yet just use Nuke Wrap Which basically will put a php/html/whatever document into an ifram for you.

Or you could try vWar (which I see by your post over at nuke forums you have already seen. But vWar is almost an entire portal in itself.

Anyways just some suggested places to start your research. Good luck!