this is really dependent on more variables than you have listed, such as base material, filler size and joint design.  The easiest method to determine this would be to machine some test plates of your desired thickness and give it a shot.

I've used plenty of semi auto and automated seam welders, but it's been several years since I did one for SAW.  My guess is you could, or easily adapt the machine to carry a second torch with the correct wire or a GMAW system to really hit the sweet spot.