Crank bearings

[Sr50 minah]

What bearings should i buy for a pretty powerful mid-race moped? Hebo manston, yasuni c21.....
I saw some Stage6 skf, Polini skf are they any different or just basic skf bearings?

 

[eurokit]

They are just basic skf bearings sold by different companys with a raise price tag.
Cant really see that there would be any difference between them.