Preamplifier options - seeking help to determine which one

Hello everyone

I have made a number of posts already and I hope you are not yet annoyed with all my beginner questions. 

I will proceed with a Yamamoto amplifier and I will need a preamplifier with a phono stage that allows my Denon 103R. 

Yamamoto makes two preamplifiers

1) Yamamoto Sound Craft CA-03 Vacuum tube preamplifier with built-in tube phono encoder 

2) Yamamoto Sound Craft CA-04 Tube Type Line Level Preamplifier

Ad. 1: This preamplifier is more expensive that CA-04 and it comes in two versions: Double volume adjustment or Level Attenuator - the latter being a bit more expensive. What is the difference here and what do you recommend me to choose? 

It allows for MC pickups but "Since the maximum output is about 28V, it can be used not only for MC cartridges, but also for MM cartridges with large output and MC cartridges with high output" - will it be a problem to use a Denon 103R with low output? Will it be necessary with a SUT to make the Denon 103R to perform better?

Ad. 2. This option is less expensive. It seems more simple but I'm not sure what the difference to the CA-03 really is. I guess I would need a external phono stage or a SUT to allow my Denon 103R in the system.

Bonus question: I use an Apple Airport (yes, I know) to stream from Qobuz. Can I use the Airport with both options using an AUX or CD input just as I'm doing with my current Sansui AU 9500? It's just to be sure.

Thank you very much. I hope you can help me elaborating on the differences and explain the different terms (attenuator, line amplifier, etc.).