The Rega Exact 2 will be a perfect match for the Rega arm on the RP8, with all of the parameters for alignment and VTA optimized with its three point mount. While the Ortofon is arguably a better cartridge, getting it setup optimally in the Rega can be more challenging. It's stylus profile is somewhat sensitive to proper VTA, and may require the use of a tonearm spacer at the base of the arm to get it right. So my suggestion is that if you or your dealer are able to set it up properly then go with the Ortofon, but if you're not the Rega is still a solid choice. Good luck, Jake!