I think Hiku's best position is fullback, but he'll end up in the centres.
When the time comes that we no longer have Snake (either through leaving the club or retiring) it'll either be Gutherson or Turbo Tom at fullback. I haven't seen Tom play, but from what I've read of his speed (and seen of Gutho's), I would think Tom is faster. I'd imagine he isn't called Turbo because he'd struggle to beat Marty Bella over the 100.
Personally, when we no longer have Snake, Killer or Skivy, out of our current lot I wouldn't mind seeing our backline as:
FB - Peta Hiku
WG - Clint Gutherson
CE - Jorge Taufua
CE - Cheyse Blair
WG - Tom Trbojevic
Though using those 5 it'll probably be more like:
FB - Clint Gutherson / Tom Trbojevic
WG - Jorge Taufua
CE - Peta Hiku
CE - Cheyse Blair
WG - Tom Trbojevic / Clint Gutherson
Hopefully though, its a problem we don't have until Snake retires. Though FB isn't the big problem for us that it was in 2009-10 when we were forced to move Robbo off his wing before Ben Farrar got the job. At least now we have 2 or 3 good fullbacks to cover if Snake gets injured, though none are yet in his class.
Just to add....Clint may have had a dirty game against the Junior Kiwis, but I'd be willing to bet that even the likes of Wombat, Rowdy, Ridgey and Snake had their own bad games. Hell, even the great Clive Churchill probably had a few games he'd rather have forgotten.