Personally I think Toulouse would be a shot in the arm for the game in France and over here.
Commercially they are probably the strongest option, they are surrounded by towns and villages that play rugby league so I think we will see an increase in the number of French players in the competition (albeit there will be plenty of English / NRL based players in their squad no doubt). I also think it gives us the best chance of increasing TV revenue.
Of the rest I think it's too early for York or Newcastle, they are progressing well and I think it's important they don't try to do too much too fast. Let them keep building foundations.
Bradford I'm sure will make it back up to SL eventually, but again I think it's too soon from their recent problems and they still have issues around Odsal and i'm not confident their owners have the financial clout to not see them in the same situation in a few years.
London have a good shout based on them being the last club to leave SL and the club that replaced them have been removed. But their stadium is poor for SL and despite having 70% of their current squad coming from their own academy being a great achievement, I think they will struggle on the field without serious investment.
Leigh could probably come in and sign a host of SL standard players and do a decent job.
Featherstone I'm not sure, there are already 2 clubs in that area, I'm not sure a third is the best option for the sport. If they win promotion fair enough, but I think if we are placing a team in, I'm not sure they are the option.
Halifax, no I don't think they would cope very well.
So I'd prefer Toulouse, if not them, London or Leigh I guess.