I think it's useful to look at how the Project might assign roles for aircraft
1. Reconnaissance.
It's far more efficient than looking from the ground
2. Light Personnel transport.
Getting a team of experts to where they are needed
3. Cargo/Logistics.
Sometimes you want to get supplies to a team that has used up its caches
4. Telecommunication.
The "poor man's satellite" Radio relay. TV/radio transmissions. Maybe even internet
5. Casevac
Transporting people to where they can get high-quality medical care
Ideally, the Project would like STOL and rough-field capabilities
There are several twin-engine utility planes that would work in these roles. My personal favourite would be the Britten-Norman Islander.
http://www.britten-norman.com/islander/
I'm sure every PD has their own preferred aircraft