Going according to Cricketweb's list:
The first team has three out of the top six in the top 10 batsmen ever, and five out of the top six in the best 15 batsmen of all time (Gavaskar, Richards, Chappell, Pollock, Sobers). The only relative weak link is Greenidge/Boycott, with Boycott still superior to any of the second XI openers.
The second team has Smith/Sehwag and Hayden outside of the top 30 and Kallis outside of the top 15. Two out of the top six are in the top 10 and three in the top 15 (Ponting, Tendulkar, Lara).
Gilchrist at 7 is a great asset, but balanced if not overtaken by Knott, Imran and Hadlee at 7, 8 and 9.
So clearly the first XI has a better batting lineup.
Pace bowling is close. Marshall is the best pacer, Hadlee and McGrath are near equal, I personally think the best combo is Ambrose and Mcgrath opening with Wasim as third seamer, but if we choose McGrath/Ambrose/Steyn then I would say the pace attacks are somewhat equal with a slight edge to the first XI.
The last bowlers will be Warne and either Lillee or Underwood.
Choosing Lillee swings the first XI a definite advantage on anything except a spinning wicket. Choosing Underwood means it will be closer unless we allow uncovered wickets, but I dont think the spinner will be the deciding factor.
I think the first team wins.