450 electric best performance for price and convenient. Frankly any gas type helis are just far too dangerous. Note a few tragic accident globally, people die from big helis. Not with it.
If have money then join a club and fly gas but not in general public areas.
Understandably gas helis are more stable and easier, but that's exactly the opposite reason to fly gas. If skills not good enough better to learn on flight sim well and then fly a smaller size electric than to fly a big heli hoping that it is easier. Sorry for voicing out, small helis are really very good for most weekend fliers., big gas he lies are for professionals to fly at proper clubs with good guidelines on safety.