Indeed, V4REV does not have such methods. The only way to work with any "set" is using an "iterator".
Please, see the examples - tableBrowser.rev, ShowSet method.
It would be something like this one:

put VSet_Count(inSet) into recCount
put VSet_MakeNewIterator( inSet ) into setIteratorRef

repeat with i = 1 to recCount

if i = 1 then
put VSetIterator_FirstItem(setIteratorRef) into recID
else
put VSetIterator_NextItem(setIteratorRef) into recID
end if
...
end repeat