Working for a commercial and industrial electrical contractor, we go through strut like it water. When in doubt use strut. There are many different manufacturers of strut. The channel nuts, or spring nut, lock in the framing member, making it easier for you to align it with the bolt.
Check out the B-Line catalog for more ideas. http://www.cooperbline.com/product/PDFL ... /index.htm
Sources for more specialized fittings:
www.graybar.com
www.fastenal.com
www.grainger.com
Any electrical or HVAC supply house will carry this, but be aware, they are wholesalers for contractors, some will not sell retail to non-contractors.