After feeling my 1700f start going over sidways while I had a load in the FEL I'm thinking I need a ROPS. After seeing the prices I'm kicking around building one. It looks like I can secure it to the rear axle mounts by using a flat plate. Then weld a U shaped piece to them. Right behind the seat weld a cross bar. My question is what material to use. Round or square tubing and what thickness?