I'm going to be building a single or possibly 2 tier brew rig out of 2x2 steel tubing, using 3 kegs. The only casters I can find here in Canada are only rated for 115lbs each, will this be enough for me to be able to do a 10 gallon batch?
I used cheap 121lbs casters from harborfreight on mine. It's a five gallon eHERMS system and the frame is 1.5" 16 gauge square tubing, so mine is a little lighter than you're planning. If those are the only ones you can find and you're concerned about the weight, you could add a set in the middle so that you have six casters instead of four. That will help distribute the weight better.