You can't use an external DAC for SACD or DVD-A playback. DACs decode a 2-channel PCM signal, not SACD or DVD-A. You need to have a SACD/DVD-A player connected to you pre-amp/processor using the analog outputs from the player, not the digital output.
The value king of SACD/DVD-A players are the Oppos. Lots of folks are using stock Oppos as transports adding a DAC for CD playback. You would then use the analog outputs of the Oppo connected directly to your pre-amp for SACD and DVD-A. I have an Oppo 970 with EVS level-2 mod's. It is excellent with the mods. However, with the mod's from EVS, you likely wouldn't need to purchase an external DAC at all because the 2-channel CD playback is already excellent.
The value king of SACD/DVD-A players are the Oppos. Lots of folks are using stock Oppos as transports adding a DAC for CD playback. You would then use the analog outputs of the Oppo connected directly to your pre-amp for SACD and DVD-A. I have an Oppo 970 with EVS level-2 mod's. It is excellent with the mods. However, with the mod's from EVS, you likely wouldn't need to purchase an external DAC at all because the 2-channel CD playback is already excellent.