Here's the useful load data that I've found out there:
R-66: 1400ishlbs.
505: 1500lbs.
EC-120B: 1590lbs.
AS350B3e: 2200ishlbs.
Of course... there are a lot of other factors... PRICE for one. Glass cockpit, FADEC, DOCs, cabin volume, what kits you have on (as JohnR81 mentioned), what altitudes you deal with (I'm assuming UK)... etc.
The 505 would probably be my choice for the best bang for your pound/euro out of these aircraft, but it all depends on what your planning to do with it.
Last edited by PhlyingGuy; 16th Jul 2014 at 16:29.