Airliner sounds

I was wondering how different the 757 sounds with the Pratt Whitney 2037 type engines vs. the RR RB211-535E4 type turbofan sounds inside the cabin and outside as well. For the Project Airbus A320 I am using the CFM sounds since there isn't any IAE sounds yet, but how different are these sounds comparing the two?1. Where can I find the sounds for the 757 using the RR?2. Where can I find the sounds for the MD-80 variants with the JTAD-200 series turbofans from Pratt Whitney?Any info on this would be helpfulThank You,