I would think very unlikely to be 139. If it is to be a common airframe for SAR/SH, the 139 is far too small.
Also very unlikely to be S92. The tender specs were written around S61/Sea King performance so anybody bidding S92 would be way way overpriced compared to other contenders.
I'd put my money on an older model Super Puma, or the enduring S61 herself. It's pretty hard to beat the 61 for the type of SH done in the FIs. She's just getting a bit slow and lacking in payload for the longer range SAR role.