My company is a non-profit organization. Currently, we have SIMPLE IRA. But we will be over 100 participants of the retirement plan. So we will have to change to 401K or 403B. We have about 70 office full-time employees and around 300 part-time employees. We will match the employees' contributions, so we want to limit the number of eligible participants. Such as, we want full-time employees to be eligible immediately, part-time employees with variable hours to be eligible either half-year or one year later. Can anyone give some recommendations about which plan fits us better the 401K or 403B? And what are the pros and cons? Thanks. Sorry I couldn't type in Chinese.