Ramsey will do well to get anywhere near Fabregas' level, so there is nothing to gain by picking him when you have the finished product available to you.
Walcott... not for me. He's still got time to live up to the hype, but on the evidence we have so far (and his injury record), it's not looking likely, is it?
Arshavin is very good, but he's not a superstar and age counts against him anyways.
So it really just leaves Van Persie and Fabregas. It has to be Fabregas really.
Whilst we could quite happily accommodate Van Persie in any position across the forward line, his age, injury record and the utter shitness of our midfield counts against him. If Aquilani is as good as he's meant to be, maybe I'd be inclined to think a bit harder about it, but as things stand, it really is no brainer.