I've not heard Sanchez speak of his willingness to work with Guardiola at City yet.
Yes it's true that City are Assembling a great attacking side that walk on water, but you can't can't honestly say that we're not building a decent team either. If we Keep De Gea from Madrid and add a Sanchez type attacker with a Fabinho type midfielder.. we will be right up there come April. We've got a deep refreshed squad now so it's only a few constituents here and there to make us title challengers.
Don't think you'll challenge for the title, but you have one of the strongest squads in terms of depth so top four is a must given the amount of money spent. I think Lukaku will do very well for you, his goalscoring record for Everton was exceptional.