Yes, the CA is stiffer and has more knots. I got my first rope halter at tractor supply, stiffer rope, less knots, worked fine. I have a parelli one which is softer, less knots and works fine too, but that's because my horse and I are more exp now. I suggest stiffer material to start with, and yes you can get nice ones on ebay. It will depend on your horse whether attached lead with no metal snap will be effective. I did fine without the extra metal, but the best lengths are 12 ft parelli, or 15, CA. 12ft is more manageable. Any shorter your horse will not have room to drift, and you will have less room to step away but still remain connected and in control if things get ugly.
No matter what kind you use, it won't not be effective unless you understand how and when to apply and release pressure--"it is the release that teaches"
Hope that helps and good luck.