Leicester, Boro, Burnley, Notts Forest. Take your pick, because the league is so open its not too dificult to achieve promotion with any team, excluding maybe Scunthorpe.
On a free transfer you can get:
Febian Brandy - Striker, Decent back up for the bigger teams and an important player for the smaller ones
Adriano Basso - GK, See Brandy
Sean Thornton - CM, decent rotation player, chips in with some great goals and has a lethal long shot
Donal McDermott on a loan is also a great signing.