Those numbers do look good. You said the TT was not fully loaded, but what about the SUV. Did you have your family in the SUV when you got weighed? I think that is more important than loading up the TT.
Either way, looking at your weights, I would recommend you look at a 6K WDH setup. I really like the Equalizer setup. The e2 series is cheaper than the original and performs very well.
http://www.fastwaytrailer.com/e2-hitch
The 6,000 lb setup would have bars rated at 600 lbs, which is near the 550 lb tongue weight you showed. If you look at what brands / designs others are using, stay in the 6K range for your setup.
I think you will benefit as much from the sway control of the e2 (or similar setup) as you would the weight redistribution.
Definitely re-weigh with your family in the SUV if they weren't with you the first time. IF that was the case, you may be surprised as how much your numbers change with the front and rear axles.