To be honest, you're asking for quite a lot for HD audio from a surround amp at that price, let alone a USB port!
I've done some searching and found the
Yamaha RX-V465 which has HD audio and offers Bluetooth playback but not USB. In fact, the cheapest amp I've found which has a USB input is the
Pioneer VSX-819 - this can also decode Dolby TrueHD and DTS HD Master Audio internally, so it's the closest I think you're going to get at around £450.
NB - I've no idea what these amps actually sound like!