What is Liverpool's best centre-defensive partnership?

On deadline day, Brendan Rodgers made swoops for PSG's Mamadou Sakho and Sporting Lisbons Thiago Lllori, further bolstering Liverpool's defensive ranks.
Kolo Toure, an earlier summer aquisition; was another smart signing from the Northern Irishman, the solid Ivorian has bags of experience. Starting LIverpools first two games of the season, the former Manchester City star was instrumental is helping Liverpool keep two clean sheets. But in a midweek league cup tie against Notts County the 32 year old picked up a groin injury - which ruled him out of the following weekends 1-0 win over rivals Manchester United.
Out-of-favour Martin Skrtel played alongside the ever present Daniel Agger against the Red Devils, and the Slovakian's inclusion played dividends,he put in a solid shift and was arguably Liverpools man of the match as Liverpool topped the league going into the international break.
So with plenty of backline options no defenders place is guaranteed at Liverpool - who have gone 417 minutes without conceding. What is Liverpools best centre-back partnership?
New signing Tiago Lllori, at 20 years old is one for the future, he will get his chances in domestic competitions and the odd league game to gain experience. Despite Skrtel's performance against United - the arrival of another centre-back Mamadou Sakho, and Kolo Toures return from injury will see him pushed further down the pecking order.
Daniel Agger - being vice captain should be confident of keeping his place in the team, but who will join him? Sakho, the £17million signing from PSG? But if Kolo Toure is fit for Monday there will be justified calls for him to be returned to Liverpools XI.
Sakho, like Agger is left footed -and is used to playing a defensive highline, something with Brendan Rodgers implements. There are concerns over the pair playing as a defensive duo as both don't have much experience playing as a right sided centre-half. But the only solution to this problem is to get them playing together as quickly as possible.
So Sakho and Agger should pair up for the trip to Wales - Kolo Toure is great back-up if needed, and lets not forget Martin Kelly is to return from injury soon and Andre Wisdom will be better with age. Liverpools defence - without the retired Jamie Carragher, looks as stong as ever.