The ABEC rating is used only in the US and has no meaning for bearings that are not rated/ sold in the US. Therefore I wouldn't really bother with the ABEC ratings for now. This is especially true for the usage of these bearings in bicycles. The beauty of BB30 is that the bearings are generic off the shelf bearing sizes. The bearing number is #6806. You can reuse the circlip, just purchase new bearings and replace.