I have a buddy who used Hockey pucks as supports, drilled through them for the anchor bolts and there u go
Can you provide a link to the book? Can't find it, even on Amazon.You definitely want to get it up off the floor. I would either bolt into two walls in a corner or build a brick or cinder block pad under it with a couple of open spaces in the blocks to run bolts through and then bolt into the floor with the biggest bolt anchors you can find. Or both. Inside corners are good because you can deny thieves the ability to use a crowbar on the side of the door that swings out. If they can pull it away from the wall and tip it onto its back they can get it open very quickly. Also if you can camouflage it with a fake wall or something so it's not visible to the smash and grab punks. I have built hiding places in past homes by framing out a fake wall covered in pegboard and installing a door covered in pegboard with tools hanging all over it that opens to reveal the hiding place. Use your imagination. A great book full of good ideas is titled Everybody"s Got Something to Hide. The guy who wrote it worked in New York and built hidey holes of every size and desciption for clients.