Manfrotto make excellent tripods, but do they now use Arca-Swiss quick-release connectors? In the old days they had a proprietary quick-release plate. Arca-Swiss configuration is the one used by many these days and has been a sort of "standard" for some years now. A couple of months ago when buying my new camera I also bought an Arca-Swiss type plate that would work with my not-young Gitzo tripod. Works great. Today when buying my new lens I had the store swap out the existing foot for a Wimberley foot that includes the more-or-less standard Arca-Swiss configuration so that I can easily slide the new lens right on to the tripod when I need to do so.
If Manfrotto has now adopted the Arca-Swiss style, go for it! If not, look around at other manufacturers who do use that. I'm not up on current tripod manufacturers and such, so can't offer any names, but over the past several years the names Arca-Swiss and Gitzo, Really Right Stuff and others come to the surface more and more frequently.....
At the moment I have a Gitzo tripod with a Really Right Stuff ball head (can't remember, think it is the 55) on it. In the past I had another with a Wimberley gimbal head on it; that combination I sold a while back and wishing now that I had not!
Depending upon the types of environments in which you'll be shooting and also the type of shooting you'll be doing, yes, stability is the number one consideration..... Also, though, yeah, weight of the tripod and whatever kind of head is on it, not to mention the weight of the lens(es) and the camera body is important, too, if one will be trekking all over the place with this stuff.
Carbon fibre is lighter weight, but tripods made with that are also more expensive. It's an important decision, not to be treated lightly, taking into consideration what you want to do with the gear mounted on the tripod, the most likely circumstances under which you'll be working, and how much money you are willing to spend, etc., etc. If you're not shooting BIF and wildlife you don't really need to be thinking about a gimbal head. If you're shooting macro and other types of images closer to home you don't really need to be terribly concerned about light weight. If you're shooting landscapes out in a field somewhere you might need to think about not only the weight of carrying the tripod but also how much weight it will support and how stable it will be during the shooting process.
Good luck with all this!