If it's 4 pin cobra type it shouldn't require anything to be re soldered. I could be wrong but I think most common 4 pin mics are wired this way. As in it should work with your Galaxy radio. As far as quality goes I don't know if it is worth it for the Galaxy radio, but I would say yes it's a good thing for the kenwood, depending on which mic you choose. Shoot it may sound great on the Galaxy, but not as good as it most likely will with the kenwood as you can taylor your tx audio much more with the kenwood. JMHO. They are nice headsets and I have heard some using them with exports like the anytone 5555, and they sound great if setup right. Some processing and compression may be needed for full potential of audio quality. I am by no means an expert on this subject, it's JMO. Also as far as leaving the headphones unplugged a bit to get the sound out of both of them, I've done this as well and found having an extension helps a bunch. A 3.5mm 6ft extension cord helps. And grab a couple ferrite chokes and wrap around. I have found that feedback is more common with having the headphones plugged in like this. Almost like talk back LOL. Best option might be to build a small box with a 1/4" and 3.5mm headphone jack that has both grounds and positives made to mono. Then a wire with a 3.5mm mono jack on the end of it to go to the CB speaker out jack or any radios ext. speaker jack that is 3.5mm. Just some food for thought. I am not a big fan of the stock kenwood mics as they sound horrible with my voice!! Now my Icom HM-12 stock mic rocks! Others have used the kenwood mic and don't sound bad at all, but it doesn't like my voice. Could be the radio as well. Old ts140s.
Personally I want to try one of the Heil HMM hand mics. They are a regular handheld mobile type mic but have both condensor and dynamic style mics as well. The Handi Mics look pretty nice as well at only 4" tall. But they aren't headphones with a mic either. Not sure which set you're looking at?? At any rate keep us posted if you do decide to get a set!! Good day.