Which Preamp?

I would go with the DeHaviland Ultraverve.Incredible sound and customer support to die for.

I would make sure to gather the input impedance along with gain and any other important specs on the Audio reasearch and then at that point call the manufacturers to see how their linestages may match up. I would also consider maybe the Herron (new review by Roy Gregory in the New Hi Fi plus) or the First Sound, which I happen to now own. I know the Hyperion only on its good reputation, but IMO you may want something a bit on the warmer side to match with the ARC.