Because you just made clear that you have the resources to do better on the criteria you set out -- if you care to -- than you are ever going to do with the Denons, which are not particularly good headphones to begin with.
Stax SR-007 - Wikiphonia
Stax SRM-717 - Wikiphonia
Otherwise, you don't really have many more places to go with the D7000s. If DIY is out, then that rules out an AMB Beta 22, which would probably be the standard recommendation. On the tube side, you could try the Eddie Current Zana Deux.