As far as goalies go, I'd reccomend no-one Bogdan Lobont. Just found him in my most recent game, been a revalation. Conceded 14 in 20, average rating 7.35. Has yet to concede a goal in a cup match, and I'm coming up to the league semi's now. Something like 3 mil should nab him. Enyeama's also good if you can get him, usually doesn't want to leave.
For DM I'd say Fernando of Girondins Bordeaux or Flamini from Arsenal. Both have the ability to act very defensively, and both have the attacking stats needed to start a quick counterattack. Flamini can be gotten on loan or for less than his value at the start of the game, Arsenal just never use him. Jean II Makoun is amazing, don't know if you could get him though. Try luring Denilson from Arsenal, at such a young age he has some impressive stats, never seen him actually play a game though.
The DMs I've listed above all make good CMs too, due to their attacking ability. Cazorla and Guti are both skilled players I've been able to get into talks with for ridiculously cheap (could probably get both for under 10) but they love their clubs, and might be unwilling to come. Definately worth a shot though.
On the wings I've grown fond of Farfan and Belluschi after they've given consistent form in every game I've played (and if I dont get them myself, someone else always does). Farfan is great cover, capable of both flanks and scoring up front. Belluschi is really only exceptional on the right, but he has a class shot (so far 2 goal of the month awards I've seen from him) and scores when you need it most. Ménez is a great prospect who can run the ball past a defender easily, and if you train his passing and crossing could easily be superb.
Up front it depends what you want. I've been impressed by Kikin Fonseca, Salvador Cabañas, and Dean Ashton. None of these guys are ridiculous goalscoring machines (since the game loves pace so much), but they'll bang them in reliably, Deano being a challenger for top
prem scorer in my current game. Vagner Love is pacier and more expensive, but can be quality in a purple patch.
Keep Martins and Owen. They're both sensational when on form. Hope this helps.