I used this product from Coralife.
http://esuweb.com/cardfile.asp?ItemN...lationship=314
If you can modify it to suit your needs, it works perfectly.
One the end of the cable is a "bolt" which in the picture is attached to the curved pieces of metal. This bolt easily comes undone and then can be mounted onto any type of fixture ( drilling or some other method)
The best part about it is that it is fully adjustable. The "bolt" has a button that when pushed down allows the fixture to slide up or down on the cable.
That way you can slide your whole fixture up out of the way when you want to do tank work. It also allows easy fixture height adjustment.
I felt its price wasnt to bad either $24.99.