Same as Bikendan. I'm around 600-700 and use the 1,000lb bars.
I called Progress Mfg once about this and they stated their bars can take much lighter weights than stated. Its the max weight you do not want to play around with. I believe they would also advise the 1,000lb bars for you from what you described. By the way, they are a very helpful organization to talk with.
Also, keep in mind that the UVW of 4,900 will probably become 6,000 plus once loaded for camping. At 10-15%, your tongue weight will become 600-900lbs. There is probably no need for you to be at 15%, but I would bet the TW will be more like 700.
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD