My experience, ordering stuff back order from hobbyking seems to require some patience. But usually once they release it on your order it shouldn't take much longer. I've waited months before for backorder stuff.
I've used 72mhz in rc combat and have gotten some antennas cut. I've had pretty good luck soldering them back together, but once they get broken in more than 2 or 3 places, I usually just replace with a new wire and very carefully solder at the receiver board. You can't get too sloppy with the receiver board joint, but if you're careful and if you make the wire the same length as original, you will be alright. One splice though shouldn't be a big deal, but I highly recommend soldering it though, I wouldn't just tape it.