Amp recommendation

I’m looking for a recommendation for an amp to use with a pair of Acoustic Research AR-91’s. I’ve read that they are power hungry but I need a little direction. This will strictly be for 2 channel use, a mix of CDs and vinyl. The room is roughly 10x15 and listening distance will be fairly close. Current equiptment includes an Arcam 300 and a newer low-end Onkyo. Do I start from scratch or add an amp to the Arcam? 

Thanks