The Aphelion 2 is a massive upgrade from the Apheta 3 and I can't understate the word massive. I have listened to this combo in a very high end system and it is very good. The P10/Aphelion 2 will exceed many much more expensive analogue front ends - outstanding value for money.
If you have a P10 I would strongly recommend the Aphelion 2 over the other options simply because you won't have to wrestle with VTA adjustments on the Rega arm which can be difficult because you have to remove the arm and use spacers when you use non Rega cartridges.
Then look at phono stages to match the Aphelion 2.