20mm spinner bearing and press fitting

[mattsdragons]

Close to ordering the final materials for my spinner, want to find out the best bearing I should use for the disk if anyone can recommend me some good ones?

Also, how would I go about fitting them into my 20mm nylon at home? If that isn't a method I can do, what would be the next best thing?

Last question, for shafts would I be better off with Stainless Steel or Silver Steel rod?

Thanks
Matt