The only one that in my opinion may possibly come close (with a fair bit of hacking) would be
MPortal, which has a tight integration. There is also
Joomla
which integrates quite nicely, but the displaying of vB components on the front page may be an issue..

Or you could consider
vBPortal which, contrary to popular belief, can display as many or as few columns as you see fit! I used to use vBPortal myself, still got the license, but have transferred over to vBAdvanced, which in my opinion integrates easier, and more pleasently and, along with GARS, is infinitely easier to enhance and offers a better experience.
Choose well m8, there are plenty of options, and probably lots more advice on it's way....