I got rolls of 2" hook and loop Velcro and the metal hardware from this company, StrapWorks.com:
http://www.strapworks.com/Hook_Loop_including_VELCRO_and_other_brands_p/v.htmI had a local upholstery shop sew the loop in one end of the long hook piece and a short piece of loop on the other end. The kind of strap that is hook on one side and loop on the other does not work well in a metal loop situation.
I used it for a a 46" TV. Also had a piece of 1" that I got off of something to hold the movable TV arm in.
I have to be careful not to overtighten these as some of the thinner flat screens are somewhat flexible. This TV was right over the axles of a fifth wheel and did not have shocks.