I used that industrial strength velcro on my adjustable liner. I put 4 "loop" pieces on the inside dome of the helmet, and 4 "hook" pieces on the arms of the liner. Seems to work fine, it hasn't budged in 9 months.
I heard you can take a construction hard hat and cut the brim off and the top off and leave the ring that holds the mounts to the head pice. Then epoxy that into your helmet. thats what I am doing. Hope it fits in the next helmet though. My white vinyl Bucket Don Post Bucket isnt big enough.