I don't have any truss yet. I have only used the TV once, and I set it on a table right in front of the DJ booth. I bought the TV for the house, but figured it was a nice enough unit, I would offer it to my customers.
If you have the manual, or can look up the model number on the Sony website, I think the screw specs should be listed. Either that, or go to Lowe's/Home Depot, and buy a couple of different lengths and test to find the right fit. However, if you can find the manufacturer's information, I would definitely use that for screw selection. Good luck!
Sween: What is the best, easiest, cheapest, most efficient, quickest method of mounting 50" LCDs?
sss18734: Duct tape fits 4 out of your 5 criteria...