I have this underpinner and I bought it from framingsupplies.com. Mine is the SE version. I don't know the difference, but mine came the support wings that bolt on to the side.
So far, I like it a lot. The tube steel frame seems plenty solid and it does a good job pinning. You will, however, need to get a feel for this machine to use it correclty. With softer woods, you have to go easier or crush the wood a bit. After a while, you can feel the cycle as you push the foot lever down and get it right every time. I learn quick, after compressing a corner of a soft frame, I never did that since.
John