Hazard for the left wing if Chelsea are willing to sell to us for a price in the are of £40m, more would be insane though, he is good but not that good, there is a reason Mourinho is fed up with him, I've seen him in the Belgian national squad aswell and always had reservations about his attitude. Talent is clearly there though, so with the right manager in front of him I still think he'll turn out to be a very good player, but he doesn't have the attitude to be the next Ronaldo or Messi, let that be clear.
If we were comfortable with the options we'd have on the wings, I wouldn't even go as far as £40m or make an offer him in the first place. But we need quality players, we can't be sniffy about attitude problems, Hazard is PL proven and if Chelsea want rid, then we should be in the market, £40m seems about right, if they want more or don't want to sell to us, than that is that. PSG is the most likely destination I think if he is leaving, he said himself he'd wanted to play there and PSG can afford him easily. Not sure he'd want to move to us though, seeing as how we aren't in the CL and we are in a rebuilding face, the only way he'll come to us is if PSG have other priority targets and need to watch their spending for FFP.
Oscar, I'd welcome him if we don't have to pay too much money for him (around £25m max). I think he would be a great player in a 3 man midfield with the point facing backwards (Carvalho-Mata-Oscar).
If anything is true about Mourinho being fed up with Matic, I'd take him aswell, I'd even consider Salah if he doesn't need to cost more than £12m, could be a great Nani replacement.