[UKBusinessLive]

If you want to place the tabs below the navbar you could try and add it to your navbar template at the very end (Although i've not tested it!)

AdminCP > Styles & Templates> Style Manager> Your Chosen Style> All style options> Edit templates> Navigation / Breadcrumb Templates> navbar

Problem being if you add it anywhere else like forumdisplay, you'll lose them when you navigate away from your index page.

The thing with your site is you have a lot of black and white and where the tabs go you'd be better using the white ones