I'm not sure what is used for VCT, but burnishers are typically 1500 or 2500/3000 rpm. I have a 1500 right now and I use it to burnish concrete guards.
1,500 rpms if you're doing it once in a while and higher if you're doing it a lot i.e. every night. I don't know brands but there is a big difference in quality so do your research.