Alas, in the writeup I found about wireless units and putting them on detectors indicated that 'some' of the bluetooth units have a time lag so when the detectorist(you, me, anyone) hears the signal the coil is no longer over the target. Not good for pinpointing. Otherwise, YES what you have pictured there would be the Perfecto combo. aka - the setup needs to be tried.
The TDK WR700 headphones I have do not use "bluetooth", it is called Kleer's wireless audio technology and it works well for the detector or stereo. In fact the response from my TDK's is better than I have from my Sennheiser wireless units (I only use the Senn's for TV/Stereo).
The wired units are nice and small, inexpensive, have the right resistance, will soak up a lot of sweat in the summer/keep ears warmer in the winter but they are wired. Since I've gone wireless I feel like I've been "set free", it is such a friendly experience to not have the wires always in the way or the headset being ripped off my head. However, there IS a Perfect setup out there, I believe this, it just needs to be found. Hang in there it looks like you are getting close................63bkpkr
Addendum:
I went to google and entered Kleer and guess what, earbuds using Kleer technology ARE available even several models and different brands. However, I did not have the nerve to look up the prices as one of the companies using Kleer for earbuds is Sennheiser and Germany don't sell for cheap. I lay the glove at your feet if you dare to look up prices. But on the Kleer site they discuss their technology including the frequency of the technology, another tid bit to throw out to folks like "Carl".