Coils are still available. Just checked and they are listed on the Tesoro web page too. The plus is that if you want to change a coil you can. Don't see a down side to having the connectors.
The headphones are hard wired in and are not removable. I really like the Sand Shark headphones. I find them comfortable and they shut out a lot of outside noise.
I bought my Sand Shark used several years ago and it has not missed a beat with one exception and that was my fault. I stepped on a 10.5 inch coil hard when hit by a wave and lost my balance. Damaged the coil. Switched to the 8 inch and used that until I found a used 10.5 inch coil and bought that.
Good luck with what you are looking at!
Cheers,
tvr