there are multiple desktop and floor model centrifuges that take rotors similar to this
4x 600ml or 6 x 600ml should get you buckets in the right size.
1000ml buckets exist, but then you’ve got to use a spacer or find a different bottle.
swinging buckets are superior to fixed angle in this application, but you can generally spin the fixed angle rotors harder, so there are pro’s to both solutions.