keep in mind: it's not so much about the rating, but what you can tow SAFELY!
step bumper, 2000# trailer weight, 200# tongue weight. now, would i pull that much on a bumper ball... no way! do yourself a favor and just get the frame mounted hitch. new or (undamaged) used, it's so much safer and easier to use. and if you plan on pulling any trailer close to the 2000#, i'd also get some trailer brakes.
but that's just me.