Since the AVP700 can't handle audio over HDMI, you'll need a player that has decent quality 7.1 analogue outputs, and Arcam has none.
The Oppo BDP-95 is popular on these forum (I've never seen one myself). I'm very partial to the Cambridge Audio Azur 751BD. Both are universal players with special attention paid to analogue sound quality and stereo replay in a similar price range to your current setup's.
The BDP-95 or the BDP-93 NuForce Edition will do a really good job.
I have never seen or heard the Cambridge 751BD.
But since Cambridge Audio claims that it features the same technology that has made the Magic DAC popular, I would urge to keep your hands off that one !
I never heard a sound so bad than the one coming out of my Arcam CD23T used as a transport and partnered with a Magic DAC.