Navision and Fund accounting

One of the companies that we manage in Navision is a Fund with few hundred participants. We receive money for them and then disburse the funds to the recipients. At the present moment we use a Global Dimension to track them (where Dimension Code is their Social Security number and Dimension Name is their First and Last name). These creates some inconvenience - we can not even store their address simply because a dimension does not have a card of any kind. What would be a recommendation on how to treat these participants - do we better off switching them to customers (vendors?) or…? Please advise. We would need to have some kind of history for each of them - how much we paid them, what is the remaining balance, etc.

if you have to pay to them, I would prefer them as vendors and use the hole stuff of vendor balancing. History and so on is then included.