Neither - the best upgrade for any rega is an Audiomods arm. It makes any rega TT sing. Then you can look at other upgrades because only then will you be hearing how the cartridge and phono stage is actually capable of..
I invested in an Audiomods series three 12 years ago and I have never looked back - truly astonishing - and the new arms are even better
Check them out - audiomods.co.uk
Here's my review - Audiomods Tonearm | My Audio Alchemy (image99.net)
My cartridge is a Denon DL 103 modified by Soundsmith and my Phono stage is a Simaudio Moon LP5.3 RS - both are an outstanding combination with this arm
Regards - Steve