I am looking for a few different machines for my shop, but my holdup is a way to get them off a trailer once here. So my plan is to build an A frame type hoist to be able to back the trailer under it, and lift the machine off it. So I am looking for suggestions on the build. Max machine weight would be 7 tons. I figure about 10’ between the uprights, but wonder how big an I beam I need across the top. Any help is appreciated.