On your short list of integrateds, I'd encourage you to look at two: The Creek and the Cambridge Audio. Creek amps are the epitomy of the "British Sound", meaning they tend to be very neutral and clean. Cambridge Audio equipment (I have some of their separates) tends to be very well designed and flexible -- it's a hub around which you can build a system and upgrade elements over time, finally upgrading to a better preamp/amp combo when you are ready. It also has a built-in USB port and its own built-in DAC, as I understand it, so you wouldn't have to buy a separate DAC.
I am not familiar with any of the DACs you list, but I have a Schiit Valhalla headphone amp. Based on my experience with that unit, I'd take a close look at the Bifrost -- Schiit equipment seems to be very well designed, and it is made here in the U.S., which is a plus, IMHO. Also, they offer a two week trial period, so if you don't like it, you can send it back.