You can use any ordering you like, as long as it is consistent in all your recordsets.
I would have thought you already had the current item recordset. the current item recordset would be:
rsCurrent
SELECT * FROM tableName WHERE idColumn = paramID ORDER BY idColumn
Variables:
Name: idColumn
type: Integer
Default Value: -1
Runtime value: $_GET['itemid']
NOTE: I noticed a problem in the original recordsets, i have updated them.