Having flown on the North Sea myself I am pretty sure they (Scotia, Bristow) don’t require an IR on type (AS332, S61, S76, AS365), but as always give them a call and get it from the horse mouth!. .The initial IR will require around 30 hrs flying (check JAR rules) but to get you an extra type you only need a couple hrs, so it doesn’t cost them as much!. .You might be able to get your initial IR on the Jet Ranger with the Bristow training school (if they still use it for IR training) that should work out cheaper than the twins other training schools use, give them a call.