Carl, the most rigid way is the normal way: Tube rings and dovetail rail.
http://www.365astronomy.com/images/s...OTA-schott.jpg
From Andrews Communications:
Dovetail bar, black aluminium, 200mm long, suitable for wedge mounts $29.00
MyAstroShop:
101mm Optical Tube Mounting Rings - $49.95
http://www.myastroshop.com.au/produc...sp?id=MAS-023C
Dovetail Rail, black aluminium, $45.00
http://www.myastroshop.com.au/produc...sp?id=MAS-023K