If a 505 won't carry what you want, not sure an EC120 can, either.
On paper an EC120 without floats carries 876lb in cabin with full fuel and no other options. An R66 Turbine Marine carries 862 with floats. Spec. the Lithium battery on the 66 and you can increase that to 888 lbs.
The 505 really does play it fast and loose compared to the 66 in terms of features, trim and weight. At full fuel, by the time you add all the things that are standard on a 66 (headliner, door openers, rotor brake, etc.) you are below 900 lbs in cabin compared to 927 in the 66 (without floats) and still travelling 50NM less than a 66. With the Lithium battery the 66 bumps up to 953 lbs in cabin.
No question the 505 and 120 are nicer to sit in and easier to load with cargo.