Slater is apparently switching codes, but to Union with the new Melbourne franchise the Rebels.
Inglis would be no good, he's never played AFL and brings some recent off-field stuff that we don't need to deal with (look at Cousins nowadays with all the crap constantly going round that the club has to deal with - it's distracting for the players)
Folau would be great athletically, and recently it was reported in QLD that he was looking to return to Melbourne next year (before the salary cap stuff came out with the Storm), but for a team that has struggled in recent years to get development right, do we really want to tackle a 'code switch' player?