I finally bought some Powerflex wishbones bushes for my Clio.
I had no problem to fit it on my non-sport wishbones, they're the same diameter. But it was hard to put back the wishbones on the car as the assembly with washers on each side is a little bit larger than the place on the car. I spent 2 hours fitting the first one and 20 minutes fitting the second one.
I'm very happy with these bushings, the steering is very responsive and precise.
Even if the new model is very hard (part of the new "black series" line that is engineered for track), the ride is still comfy enough with my Bilstein B8/Eibach Sportline/strutbrace setup.
The only unknown is the lifespan. I'll keep you updated afer a trackday guys.