How about this one.
Sponsons, Cheek tanks and the addition of a 600L internal tank would give it over 7,000lbs at lift off. This would give you a RoA of 260 miles with 30mins on site, room for 11 survivors, with 30mins fixed and 10% variable reserves.
The internal tank is not a problem. I have winched with one in a 332 and it doesn't get in the way.