Still working on the floating head. The rails I ordered from Ebay came in and they are tiny. They take 2.0 mm screws. Good thing there is 4 per rail on both the rail and truck. I think they'll be OK for Plasma but wouldn't be any good for anything with a heavy load. I'll use them for now but look out for something heavier.
Got the slats and rails installed. My son came up with a great idea about using angle upside down and cutting slots into one side for the slats to sit in. Worked great and was easy to do. Mark it off and stick it in the chop saw and it was done in minutes. Then I just bolted it to the other support that was already welded in and it was done.
Pics attached.
Willy