if better boards are avilable, they will be the best thing you can do to your running boards. I am 300 with my backpack, and both feet on one side, i have no flex.
The cat ones are alot cheaper for sure, I think in the thread is the part number. If you have covers for your hoses, you can heat and bend the edge so it turns back in and goes into your cover in the stock location.
I did this for Hugh on here and he rides standing up most of the time, I don't know why he has a seat. He has has no strenth issues with the sled and he jumps the thing for days at a time.