I bought some like that and took it down to our local garage here to get him to do it. He thought they looked a bit flimsy so he made some up out of a thicker gauge metal and welded them in. Charged me 200 Euros. He's done a good job. That was about two years ago and they still look solid and strong.
A good tip is to space the splash gaurds away from the footwell with some extra nuts or washers so that any water and crud can go through the gap created.