Should be Modano/Sundin. Sundin is a first ballot hall of famer, Modano will 99% chance be a first ballot hall of famer as well. Kovalchuk is well on his way, but I don't think his body of work is quite there yet.
Bolded the key term. Kovalchuk is averaging 42.5 goals per 82 games. I wouldn't even put Modano in the next three.
Still, don't call a guy who scored 50 goals "not a 40 goal scorer." I am (was?) an Atlanta fan, so trust me, I love Kovy, but he hasn't quite hit the same level as Sundin. Modano's probably a toss up -- I'd probably take Kovalchuk but it's debatable.
I don't understand the argument for Modano over Sundin, unless you're just basing it on the fact that he won a Cup.
1374P in 1499GP (0.92PPG)
7 All-Star games
1 2nd All-Star Team
1349P in 1346GP (1.00PPG)
8 All-Star Games
2 2nd All-Star Team
Sundin has two seasons where he finished higher in the points race than Modano ever did (8th). And if you really want to bring up playoffs Sundin was 0.90PPG in the playoffs, Modano was 0.83PPG in the playoffs, you can't really blame Sundin for not ever being on a team as great as the 1998-2000 Stars.