The KFI plates are a good bargain... high quality and reasonable price.
Just a bit of advice from experience... the plate as you receive it will be flat and square... the plow mount you are welding it on might not be. I welded one onto a fork frame that I had fabricated... welded one side fine, and the bottom of the other side was touching the fork frame fine, but there was about 3/16" space between the frame and the plate at the top. I welded the bottom and then used a large clamp to pull the plate up to the frame at the top and then welded it. When I went to hook it up to my tractor, I found that my method had twisted the plate slightly and it made it hard to make the pin engage on one side. Lesson learned, leave the plate square and fill in gaps at weld points with weld, reinforcement, etc., whatever it takes. If I do another, I will probably attach the plate to the tractor side, engage the pins fully, and then tack the implement onto the plate. Remove the whole assembly and finish welding... I think this would keep it as square as possible so it lines up properly with the tractor side.