We use both in our program. I would suggest the BK-117 if you can. There have been limitations on us here with weight due to hot weather. If you are only doing short hops that might not be a problem (use lighter fuel load). You might also want to look at your crew weight as well and also you equipment load. We do a lot of NICU flights and IABP's and the BK is much better suited to these tasks.
The big problem has been the AC system in the heat. Make sure if you go that way you get vented windows!!!!!! Or plan on wearing a camel back in hot months.
Take you time with this. Make sure you see an EC first and work through all of the details with ALL of your crew members and pilots before going in service. Highly recommend that if you do go with the EC make sure to spec it for a model 35 ferno stretcher, not the fold up job that many have. If you have used one you'll know why.
On the plus. It's quiet and maintenance is lower if you have mechs who know the machine.
