attaching rack equip to my roof

I used to have an eide boat loader on my old truck! Yes i like mounted to roof in prime locations. I am going to weld a cross bar from the side bars in the back, with two t's sticking towards the rear that over hang the rear of the camper a bit. long rollar, like the kind on front of boat trailer will bolt between the t's to rest kayak on to lift/pull up. I have a used roller from a boat trailer and also one from an old push mower. Could go crazy with some type of pulley system, but im not that decrepid i cant lift a kayak up onto my roof:)