Personally, I like 3-4-1-2 system but system is there to accomodate players not other way round.
With current team, 4-3-1-2 formation is most appropriote,
But I think lineup can change as the season progresses. Legro, Tudor could be the partnership, Zambrotta could play LB, while Camo as RM, and Maresca Appiah should give serious threat to Davids and Tach. Nevertheless, it is good to know that we have good mix of youth and experience in the team.