That is some very good home audio equipments! Seems like you are in a wrong forum!!
I was looking at the Rega DAC and its Saturn CDP before I bought my Eastern Electric DAC. The seller told me that it is dumb to buy the Rega CDP just to use it as a CD transport and I kind of agreed with him. Just curious, how do you intend to get the streaming to work with the Walkman and the Rega DAC?
Actually, had I known that you were going to use an external amp with the walkman, I would heartily recommend you to take a look at the
iBasso DX100. It has got everything you need. Absolutely everything. Maybe you could even save some money on your Rega DAC.
Yup, at the end of the day, it is not what is written on the paper but whether our ears love what is coming to it. Not an easy task to recommend a headphone unless we know your preferences and your budget =)