LOL you didn't try very hard - Google found it top of the list !
http://www.telescope.com/Orion-Dual-...nder%20bracket
If you already have say a 50mm finder this isn't going to be very secure as the metal bits are only diecast aluminium and the screw threads will strip under loads much more than one 8 x 50mm finder. Not to mention a tad wobbly.
It would be better to piggyback a cheap 60-80mm refractor if you want a bigger finder, using either a side-by-side plate, tube rings
http://www.bintel.com.au/Accessories...2/catmenu.aspx or some of these parts:
http://www.bintel.com.au/Astrophotog...oductview.aspx
http://www.bintel.com.au/Mounts---Tr...oductview.aspx
http://www.bintel.com.au/Mounts---Tr...oductview.aspx
http://www.firstlightoptics.com/astr...100-wedge.html
While the latter is ostensibly a wedge, it does go below 0 degrees (ie top parallel to the bottom plate) and it looks seriously robust compared to the Orion or Skywatcher bases, though some work will be needed to put holes where you need to attach a dovetail or larger finder (no big deal with a drill and some taps to cut threads).
And yes I appreciate the desire as I use a 100mm f/7 as a big finder (4 degree field). I align this and my scope with shims under the dovetail.