174 kg's,!you sure,just a suggestion,fit four wind down legs on the corners,22 mm all thread with a nut welded on top for ring spanner or socket as a wind up/ down handle through a 22mm nut welded to lower part of frame,you will find the castors will move a bit when you're working even when locked.
Ps,like the stubby holder too,go bombers ( what ever it takes)