Definitely Emerton or Chipperfield 

Mark Viduka

No one touches a fit and inform kewell so would have to be him.

Yes he is, very true.

If I could pick 3... 
I would say Vinnie Grella...  but I think Jendinak can cover that, with his hard ass attitude, eversince he grew that beard.

Definitely need a solid defender, and to me that would be Neil.

But ultimately we need a player who could make a difference, who could partner alongside Leckie, Cahill, Juric, Kruse,,, and that would be the Wizard of Oz,,,,  Harry Kewell.

I can't pick between Viduka and Kewell,,,can I have both please ?
The current teams problem is not that it is "letting in goals" ...it is that it is "not scoring enough".
We don't let in a lot ...our problem is we also don't score a lot .
Most teams leak a silly goal or two ...but good teams simply score three to compensate.
We don't have that ability.
I think the current Socceroos are a good footballing team ...we just lack penetration and composure up front  .
Imagine Dukes and Harry in the current team ...would be scoring for fun . They would also help others to score.
(Dukes was a master of the tricky layoff)

Viduka

Almost agree. I'd go with Moore over Neil, but other than that, a Grella type player is a must (though don't think Jedinak is is the same category). And the Wizard is the only choice up front.

If we aren't purely talking about plucking a player from 2006 and transplanting them in to the starting XI then it would be one of Lucas Neil at CB or "2006 Tim Cahill".

People saying Viduka or Kewell need to remember that Kewell was crocked in 2006 and Viduka's output of goals/per game ain't that great.

Schwarzer. We'd be scouting for a home base in Russia if he was in goals.

very good points and agree.
I dearly love Dukes for his stature/ability but at NT level he was used as the target man hold and release but not score enough.
HK was the xfactor but his injuries robbed us many times.
Both mind you wouldn't have done enough without the engine room providing it in the first place.
I can't pick just one mind you - Bresh, worker creator and could hit a ball well, Grella, the beast trenchmen mid Jedi is no where near him imo, Luca$ as many here in the past labelled him , well proves how much he's nominated here to be in the backline, a general holding last man who also could feed a ball up, we lack this type of player hugely today.
Great mentions, Lazza !, Chippers, Schwz, Emmo.

Kwell.... then Neil .... love Dukes as well... Vinney G as well 

Lots saying Viduka, yet I can't remember many important games where Dukes was the difference. Nor did he score regularly at NT level - despite playing in Oceania.

I think Vinnie Grella would make a big difference to today's team. When Jedinak plays we look a bit meaner defensively, but we are very poor at building from defense. I just remember how good Grella was at getting the ball from defense and moving it on - and so very rarely caught in possession.

Has to be Neil for me as it fixes a significant weakness, as good as Kewell and Viduka were the former was ruined by injuries and the latter never performed well enough for us