Doorfx: i haven't installed a stainless top on that long of a surface and the one i did install was made to fit a table/bench i built for a piece already bent and formed.
here's a thread where a member
(Nitro3421) where he has recently installed a wall of tool boxes and he had a stainless steel top made for them. all i remember seeing him do was tac welding the seams, but here's the thread you can maybe see how he did it and it was a few weeks back. his house and garage are pretty amazing too and you might like the read and get a few other ideas.
http://www.garagejournal.com/forum/showthread.php?p=6071600#post6071600
Brent: good luck welding that cool steel table all together and I for one and looking forward to seeing the pictures.