As Tony said bove, they do exist and are called Oggy Knobs. They are made in Australia and come in 2 kits.
1 is the typical fairing drill bolt on style, the other (which my bike has) is the no cut, heavy duty, super strong bracket version.
The bracket version comes with 3 pieces - 2 frames and 1 tension bar. The 2 frames bolt onto the engine mounts (where standard sliders bolt to) as well as another mounting point under the fairing and the tension bar bolts between these 2 frames creating a bloody solid mounting point for the slider knobs.
Here are a few quick pics I took, sorry for the crappy quality.
In the second picture you can see the tension bar running in front of the engine block and behind the radiator (the brownish looking bar).
Buck_Y_Lee made a good point about non cut sliders dispersing the impact force instead of it going directly to the engine mounts. Now I am not expierenced in motorcycle crashes (haven't had a fall in 5 years riding
YET) but to me it makes more sense. As long as the brackets create a sturdy mounting point for the slider knobs (which oggy knobs do) how could it be worse than direct mount sliders?
If anyone wants any more pics or info just send me a PM and hopefully I can help.
http://www.kenma.com.au/public/oggy.html Manufacturers web site.
http://www.kenma.com.au/public/downloads/oggy_fitments/OK536-537.pdf Installation instructions with pictures.