ARC Phono - Which one should I get? Ref or PH7

What cartridge are you going to be using with this phono preamp? (Specifically, what is the output of said cartridge?) The ARC phono preamps tend to have a somewhat limited amount of gain, so if you are running a really low output MC cartridge, (say 0.25 mv or less), they may not be your best choice.

The PH-7 has many more features than the Reference, (and more easily accessed via its remote control), so I would go with that one. As long as you don't go with a really low output cartridge, you should be okay.