In fairness, I think you can split those names into three categories, and I haven't included Dembele who we have - however spuriously - also been linked with.
Cat 1: You've got 'target men/poachers':
Giroud, Dzeko, Benteke, Dost
Cat 2: Then more pacey players capable playing anywhere across the front line:
King, Walcott, Vardy
Cat 3: Then you've kind of got hybrids of the two:
Zapata, Dembele.
So, when people say - 'we should be getting Giroud instead of King', or 'why are we after Benteke instead of Dembele', for example, just remember that they're completely different types of player and Koeman's ideal system will have a range of all of these.
Now, I think the strongest links suggest that our main priority is to get a target man type in, and ideally one with Premier League experience - which makes perfect sense.
We have Sandro who I think fits Cat 2, and Rooney who is basically our versatile striking option to play anywhere Koeman desires. What this team doesn't have at all is a big striker who can provide that presence up top.
Once we have one of those in, I reckon it'll be a case of waiting to see how the current bunch all settle (this is including Sandro, Rooney, Mirallas, Lookman, DCL), and then if we need another addition we'll go out and get a player from either Cat 2 or 3.
All a bit convoluted I know, but this is the best and clearest way I can think to get across the point of it's not about the actual player at the moment, but more about the 'type' of striker that we're after.
@MorgsGoat 's squad analysis thread is probably the best place for it, like.