Here is my breakdown of your skis, with actual comments instead of 1 liners.
Rossignol Soul 7: Great new redesign by Rossi, making this ski lighter and more friendly to advanced/expert skiers by reducing the tail taper and stiffening it up a bit. Ski is quite light for it's size and the tip taper will help in deeper snow. Low swing weight. Best suited as an all mountain touring ski imo.
SFB: I think this is the ski for you to be honest. 110 underfoot so great float in powder with tip and tail rocker, while the more classic shape with very little elliptical sidecut will carve on hard pack very, very well.
Rocker 2 108: Good all mountain ski but the elliptical tip shape threw me off a bit in tests (Not saying it's bad, the 115 and 122 rock but they should have mellowed it a bit in the 108). It felt a bit hooky to me on hard pack.
Rossignol S3: This ski is a noodle. Super easy with tip and tail rocker but only 98 underfoot. If you are beginner intermediate skier get this, otherwise look elsewhere.
I know you already narrowed your list down to 4 skis but I have to recommend the K2 Kung Fujas (Shreditor 102 for 2014). The dimensions are 133/102/127 and it's perfect for the type of riding you want to do. I felt it is very similar to the Sir Francis Bacon, but a little bit skinnier, so it is easier to get up on edge and it'll be better on hard packed. The pow performance is pretty good too, but what blew me away was how amazing it skied on hard packed and variable snow. The Bacons and Fujas are both pretty soft skis and both have many similarities, but I chose the Fujas because they have better durability in my opinion. The Bacons have a really thin tip and I know that lightens it up, but my friend broke his once because it's so thin. The Fujas scratch really easily, but I've found it pretty hard to destruct them. Anyways, just think about the Kung Fujas, I think you'd love them and they fit your style perfectly. If not them, then get the Bacons, those are the best by far on your list excluding the Fujas.