I hope you get the Ref 5se. You will feel no need to upgrade for a very long time. It is truly world class. While the speakers are the voice of your system, the preamp is the heart. It has more of an effect on the sound than the amp.
With an MC cart I would go with a PH7 or PH8. I don't think the PH5 is a good match for a MC cart. Especially if you decide to go with a low output MC. Right now I a have a Fosgate Signature phono stage and I really like it. It is highly adjustable for all types of cartridges.
I would go with USB output to a DAC as opposed to optical.
Let us know what happens.