Typically the spring bars are sized up, just as those above are suggesting. It would be best to get an actual tongue weight of your TT so you aren't guessing.
1000# tongue weight I'd go with 1400# bars. But I'm guessing your tongue weight when loaded will be somewhere in the 600-800# range when fully loaded. In that case, I'd go with 1000# bars.
Richard White
2011 F150 Ecoboost SCREW 145" 4x4
Firestone Ride-Rite Air Springs/Air Lift Wireless Controller
2006 Sportsmen by KZ 2604P (30')
Hensley Arrow