I use this style front rack and find it very, very solid. Tho I haven't tried it with 20 lbs on each side, since that would equal the weight of my entire load, I have no doubt it would handle that much. Most of the weight is supported at the eyelets of course. The p clamps and cross bar stop any tendency to sway. The panniers must use hanging hooks, ruling out Orblied type attachment systems for this rack. Other p clamp racks would likely accomodate Orblieds. Check with www.thetouringstore.com about this.

Soldering attach points would be more elegant, and open your rack options up a lot, but I don't see how that alone would make the carrying capacity any larger. Be a bunch of trouble too, including ruining the finish on the fork.