Haven't seen any weights posted by the OP. however the TT appears to be a 280OBS. With a GVWR of 7630lbs, OR a S290DBS with a GVWR of 7555lbs. IMOP, 1200lb bars will be too much. And bars that are too strong, are just as dangerous as bars that are too weak. I'd stay with the 800lb bars, and no higher than 1000lb bars. Is a better fit. Remember, You aren't moving all of it, just part of it. WHO told you your bars were too lite?
For example, if the weight distribution system has a 1,000 pound (454 kilogram) tongue weight capacity but the trailer is loaded with only 300 pounds (136 kilograms) of tongue weight with 50 pounds (23 kilograms) of cargo in the trunk of the towing vehicle, you're about 650 pounds (295 kilograms) under the rating. That can make the distribution unpredictable and dangerous. On the other hand, if the system is rated to 1,000 pounds (454 kilograms) of tongue weight but you're attempting to distribute 1,500 pounds (680 kilograms) of tongue weight, the system won't be able to distribute the weight effectively and you'll also have some serious problems. Keep that infamous rule from "The Price Is Right" in mind when choosing a weight distribution system -- you want to bid the closest without going over.