I have the floor mount model of that bender and did not want to permanently mount it to the floor either, but I knew that it would be the best and most secure way to mount it. My son works for a masonry company, so he brought home a masonry saw and we cut out about a 12" square section of the garage floor. Next, I welded four 1/2" coupling nuts to a piece of 1/4" steel plate so that the nuts would match the mounting plate on the bender. I put a bolt in each of the coupling nuts to keep the holes plugged, then concreted the new plate into the floor with bolts just sticking up out of the concrete. Once the concrete cured, it was an easy matter to remove the bolts and fasten the bender to the floor when it was needed. When not in use, it is easily removed and the a thin 1/8" plate with smooth pins fits into the coupling nuts. This keeps stray material from getting into the holes when they are not in use. The smooth pins are also a loose enough fit that they do not rust in place in the floor either. Now anytime I want to use the bender, I simply lift up and remove the simple cover, then bolt the bender to the floor in just minutes. This method allows me to mount the bender in the middle of the floor so that there is room to work all the way around it without running into any obstacles.
I had considered mounting it with anchors, but soon realized that the method that I used would be far more robust and reliable than anchors.