OK, I finally decided. It will probably be very ugly, but it will do what I need it to do. I'm going to bend and weld some 3/8" thick rebar into a low bikerack that will lock into the pickup bed thru those a tie down hole. I can get rebar pretty inexpensive and bend it to whatever specifications I need. After is it shaped correctly, I'll cover the whole thing in black electric tape to keep the metal from scratching anything. Maybe rubber coat it instead (if that isn't expensive).
Like I said, it's gonna be ugly, but I should be able to drive anywhere and not get the bikes stolen. Also, I need a winter project.