Wonderful! At last not an "if you had £xmillion" thread!
I believe the first thing to establish is which players are in our current formation that we would consider irreplacable (or irreplacable within realistic financial constraints). Torres, Gerrard, Mascherano, Alonso, Agger, Skrtel, Carra, Reina are about the extent of it.
The clear overloading in the middle of the park means and the centrebacks. We can either 'lose' Gerrard to a 2nd striker role or play 3 in the middle and lose a quality centreback for an average, traditional right back / left back.
Gerrard will be a 2nd striker one day, no doubt, but that would be a waste at this stage of his career. Wingbacks seems the only option, so why not blend both the formations previously and have a sweeper and a flair player.
I am not sure the deepest lying CB should be the ball player, I believe they should be the smartest and that is undeniably Carra. The presence of Agger (and to a lesser exten Skrtel who has proved a capable ball carrier) adds the impetus from the back with natural left and right footers.
Gerrard is not sacrificed as a 2nd striker, meaning he can continue to make an impression on games in the middle of the park with the advantage of Masch to cover. The +1 would be the flair player, the ace in the pack, the unpredicatable one that is not a striker but not a CM. I dont fear for a lack of width here as the ability of Gerrard and Torres to pull wide is undoubted and extremely flexible. Their ability to draw 2 player means that any shortage we may have in the wide areas will be compensated for.
Cantona is about the best example I can think of for the +1, not a 'hole' player or an edge of the box player but a complete loose cannon. Zola too maybe, but they are both a bit past it. Ronaldinho in more recent years, or Kaka but this is pie in the sky thinking. Aguerro may fit, but he may be too much of a striker for this role and would leave us with a front 2 which isnt my intention.
This means the addition of only 1 player to the first team, I may be in FM world and I am sure Rafa has already thought of it but I think it makes sense. I am not sure it will offer the beautiful game we are searching for, but the addition of some flair without compromising would be a welcome addition.