Haven't seen that shorter design, but might be some theory behind it. You
might change that balon to a 1/1 match, because 72 ohms is closer to the
match you will get with the zip cord.
As far as insulators, the nylon wire ties will make fine ones for the
purpose. Three supports are best but for emergency purposses, two will
do. I am sure lots more and better info on the qrp message boards.