Picking an auspicious 3 digit number

Hi, I have a choice of several mailbox numbers. They offered me 580, but I declined because I think 58 would mean no prosperity -- tho I'm not sure if the 0 would change that. The remaining choices are 236, 290, 297, 387, 589, 645. Which of these would be best? I'm not Chinese, but i do business with Hong Kong, so I understand that the number is important. Among these, I think I would pick 297, guessing the meaning at something like tranquil, long lasting harmonious relationship. And I would avoid 645, except I think 45 is actually a good number even tho it has a four in it? My Chinese is very poor, so I'm sure I'm missing a lot of meanings. Very interesting language, btw. I would appreciate your input. Thanks!