Hello mate,
2 possibilities:
First one: 4-2-3-1 with your actual squad and without changing. Cazorla will be your leader to organize the game, and behind you could have arteta and Wilshere/Ramsey. But according to me, it is missing a defensive midelfier.
Second possibility: i don't know if it is more efficient, but my choice has to be a 4-3-3, with a defensive midelfier, and Cazorla in CM (or RW). I have bought Lucas Leiva to have more strengh and experience in the middle. I have also bought Cabaye (cause i'm french), but it is not necessary. Forward, i would say that Walcott in RW and Gervinho in LW are good choices. For your CF, i recommend you a very good one, that could play in complete forward for example. Giroud is good, but not enough for me. I would prefer Cavani for example. After that you team looks almost perfect.
Try to play with a fluid approach, with controlling the match. You could allow more creativity, and more stall (i don't know if the word is correct). try also to make more short passes to keep the control. Your midelfiers could do that, because they are technically good.