I rate both Gilchrist and Jayasuriya as equals in batting in ODIs. Both had similar roles and did their job perfectly as attacking openers, which is also one of the reason why they both average only in the mid 30s. Can't pick one over the other if it comes to just batting. Balance of the team will determine whether we go with Jayasuriya or Gilchrist.
From my watching days, I don't rate Symonds bowling much. He just picked up the left over pieces of Mcgrath, Warne and the other great to good Aussie bowlers of that time
Jayasuriya is definitely a much better bowler than Symonds. On fielding Symonds beats him but Jayasuriya is a decent fielder as well. Both had different roles in batting.