hi im new on this site, have bin doing alot of reading and the work you all do on here is great, i was hoping someone might be able to help me out,i have a 1991 suburban that i would like to build a safari type rack that also doubles as a place to sit up on and hold weight of a few people,it has factory roof racks but how they anchor is just to the roof and im sure that wont hold to much weight, any ifo would be great.thanks for you time guys&girls johnny b