Hi Rick - I also have the P5/Exact 2 combo, and I have really enjoyed it. I use the Mobile Fidelity LP#9 Stylus Cleaner after every listening session, and a dry stylus brush during the session after each side.
I have heard a few different phono stages with my set up - the Lehmann Black Cube in the store, my brother's Project Tube Box SE, and my own Bellari VP129. Of the three, I definitely prefer the Bellari - it has a bigger soundstage, the widest dynamics, and a much better (more realistic) resloution of instrumental and vocal timbre, especially in the midrange. I haven't heard the NAD or the Rega. There is usually a Bellari to be had here on audiogon, almost always for under $200, so I would recommend you try that.
I have heard a few different phono stages with my set up - the Lehmann Black Cube in the store, my brother's Project Tube Box SE, and my own Bellari VP129. Of the three, I definitely prefer the Bellari - it has a bigger soundstage, the widest dynamics, and a much better (more realistic) resloution of instrumental and vocal timbre, especially in the midrange. I haven't heard the NAD or the Rega. There is usually a Bellari to be had here on audiogon, almost always for under $200, so I would recommend you try that.