I bought my CTX late January as part of a holiday special and it came with the 17" for free. I put it on when I received the detector and haven't taken it off. I love it. It works great. It is very stable and quiet. I can cover some serious ground with it. Great for parks and yards. It does surprisingly well in the trash. I highly recommend it.
Now....For the headphone situation for the CTX. I have studied this out and the bottom line, there is not a lot of options. If you want to use the wireless receiver (wm10), it has the 1/4" plug. But the machine has the 8 pin plug. So if you buy a waterproof headphone with the 8 pin jack, you cant plug it into the wm10. If you buy a headphone that plugs into the wm10, it won't plug into the 8 pin plug on the CTX.
So either you have to buy 2 sets of headphones. One for water use and then buy a headphone for dry land use.
The only true waterproof headphone for the CTX is the DetectroPro amphibians with the CTX plug. But these headphones use a pizzo buzzer for the speakers. The sound quality is not as good as compared to headphones that use the 2463 audiosears speakers. The pizzo buzzers work great for water use. But the sound quality is better with the 2463 speakers. Sun Ray pro gold's with the CTX plug and some others use the 2463 speakers and are great for land use.
But there is another option and the one I went with. I went with Mal's Surffones. These are custom built headphones made by a guy in the UK. He uses a waterproof speaker. He uses heavy duty cords with different choices of lengths. Right or left side cable. Plus he makes and adapter that allows the 8 pin plug to be used on the wm10. So you can use the same headphone for both water and land.
I haven't received the headphones yet but they should be here very soon. If you choose a another brand of headphones, he still has the adapter for sale that goes from the 8 pin plug to the 1/4" plug in straight or angled so you can use the wm10.
I like the idea of using the same headphone for both land and water. Once you get use to the sounds of one headphone, it is hard to switch to another headphone and relearn the tones.
http://metaldetectingforum.com/showthread.php?t=251943&highlight=mal's+surffones
Here is a pic.