Seems like a reasonable configuration to me. All pretty good bang for the buck but I would caution you on the DT990. While a pretty solid set of cans they have a fairly pronounced treble, owned them for many years and they don't get much use relative to my other headphones. I'm a almost daily user of the HE=500 so my vote would say the 4xx is a safer choice on the tonality front. Owned the 880, currently own the 990 ,T1 and 1350 and have listened to the 770. Of all the beyers of which I am familiar the 990's treble is the most prominent to my ears.