For a few years I used the Manfrotto 190CXPRO4 as my main tripod, first with a 488RC2 head (equivalent to the 498RC2, one step larger than the 496RC2 on your list), then with a 468MG head. Either setup is fine with a gripped body and 100-400 or 70-200/2.8. Pat, not sure if your bad flip-lock experience was with Manfrotto legs, but I've never had them slip on mine.

As Pat states, load ratings aren't that useful. Different manufacturers have different standards, and they don't explicitly say what 'load capacity' means to them. A 10-lb capacity from one maker might mean 'supports at least 10-lbs rock-solid' and realistically does fine with a much heavier load, while from another it might mean 'a 10.1-lb load will make the ballhead flop over'. So, load ratings are a good guide within one manufacturers lines, but less useful comparing across manufacturers. I do appreciate that RRS lists some specific lens combos in their descriptions.

I recently got a RRS TVC-33, BH-55, and PG-02 side gimbal - the quality of RRS gear is truly excellent. I've tried out Gitzo gear in shops, it's very good, but the RRS stuff is just slightly better built, IMO. But also costlier...

For the head, I'd skip Gitzo - their legs are great,their heads don't have nearly as good a reputation. The other issue with both Gitzo and Manfrotto heads is they come with clamps that use their own, proprietary plate systems. I'd really recommend going with an Arca-Swiss system (I have a Wimberley C-12 clamp on my Manfrotto 468MG head for that reason). If you add a monopod, the full size tripod+head, etc., you can mix and match several brands. With the AS system, I use a mix of Wimberley and RRS body plates, lens plates, an L-bracket and a replacement lens foot with Wimberley, RRS, and Kirk clamps.

I'm currently using the 190CXPRO4 as a travel tripod. It's light enough, but with the head on, it's too long to fit in carryon luggage, so I need to remove the head for air travel. For that reason, I'm actually considering the RRS TQC-14 with BH-30 LR.

One downside to RRS gear is that there are no distributors - unless you visit their shop in CA, it's buy-then-try, and pay return shipping if you don't like. But if you go that route, I suspect you'll like.