Arcam P85 / P90 with the third chanel option. Or if you are looking for an intergrated amp the A85 / A90 with 3rd chanel option.
The A85 / A90 are great for intergrating with an AV amp as they have a fixed gain mode. This means you don't have to keep on adjusting the volume, when you switch from sources hooked up to the Aracam and your Denon.