Define the mission:
How much weight do you need to carry?
How fast do you need to be able to go?
How far unrefueled?
Then see if you can find an aircraft that fits your requirements (or the most important ones.
Then see if you can afford to fly it after you buy it.
B407
EC130
AS350B2/3
B207L/B-III
HU-MD500/520/530