A standard boat lift is rated for over a ton and most have a safety mechanism built in that has a servo cog that prevents free fall in case of failure. Mine has never done anything but be reliable and my load is 3,350 lbs. while I don’t use it to support a drop down gun safe, I’m fairly confident that it would do the job without any concerns. The standard lifts will have a 2 inch fitting that can easily accept a 2 inch pipe and you wrap steel cable on the pipe and attach that to whatever you want to lift. Add a couple of Hall effect sensors to determine up and down limits and you’re golden. I have an outdoor elevator / cage (outdoor elevator) setup that has probably been the most trouble free device I own ad aside from injecting synthetic grease in the provided grease (irk) fittings ever ear has been 100% reliable. I’ve ridden in it more times than I ca count - just ran a new 600 pound refrigerator up the other day.