20 '' Modell Mbdesign KV1 konkaver (no gerade)

[Viper2011]

But these on the photo are ET 42. If you're not going to drive that low, you can mount a lower ET.
The rims on this BMW are 8,5x19 ET 35 and the spokes are more concave than they are on your photo. Although the rims are 12,5 mm more narrow. It all depends on the ET: tall ET = straight spokes, low ET = concave spokes. The wider the rim, the better...