You're gonna need a bigger bike Bubba. This thing will break. If you look under the seat or somewhere, there's going to be a sticker indicating GVW [gross vehicle weight]. This includes you guys and the bike as a package. I'm pretty sure this thing's GVW will max out way less than 280+300+500=1080ibs.
Plus, all loaded up, this bike will be way more unmanageable than a big bike made for big loads.